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THE
REIGN OF RUBBER

WILLIAM C. GE^R, A.B., Ph.D.

Vicfr-PraUwit, Tu B. F. Gooduch Confiht, AIuod, Ohio

ILLUSTRATED WITH
MANY PHOTOGRAPHS

NEW YOHK

THE CENTCBY CO.

1922

ICi NEW VO!iK
PUBLIC LIOSARV

66336A

ASTOR LENOX AND
.DSN Fi^UHDA'l'tONS
R ]"ga L

Copyi-Jght, 1923, by
Tub CBMTuar Co.

>10V W;:i|/^

This book is dedicated to

Mm. BERTRAM G. WORK

under whom the author first became
acquainted with rubber

'J*

<-■

..>

ACKNOWLEDGMENT

Happy is be who has found a wealth of cordial co-opera-
tion. Such assistance to me in the preparation of this book
has been noteworthy.

The aid of Miss Frances McQovem and Mr. W. Don Har-
rison of Akron has been especially valuable.

In the gathering of material and data many have heartily
assisted. It would be impracticable to mention all, but
among them are: Professor William H. Qoodyear, Curator
of Fine Arts at the Brooklyn Museum; the officials of The
United States Rubber Company, The Fisk Rubber Company,
The Firestone Tire and Rubber Company, The Qoodyear
Tire and Rubber Company^ The Boston Woven Hose and
Rubber Company; my associates, the executives of the B.
P. Goodrich Company, and many of the staff ; A. Q. Spalding
& Bros. ; Brigadier General Amos A. Fries of the Chemical
Warfare Service, United States Army; the officials of the
Bureau of Aeronautics, United States Navy; the officials of
the Air Service, United States Army ; The Rome Wire Com-
pany ; Mr. C. R. Boggs of the Simplex Wire and Cable Co. ;
M. A. Cillard, Editor of Le Caoutchouc et La Qutta-Percha,
Paris ; Mr. W. M. Morse, Editor of the India Rubber World ;
Mr. J. K. Mitchell, President of the Philadelphia Rubber
Works Company; Mr. Oswald Latham and Mr. Herbert
Standring of London; and Mr. W. E. Hemenover.

CONTENTS

OHAPTEB PACn

I The Evolution op an Industry 3 *

II Problems op a Pioneer 18 *

III Fundamental Methods and Machinery .... 29

IV The Rubber Man's Cook-Book 44

V Raw Rubber 63

VI Reclaiming Waste 88 *

VII The Chemistry op Rubber Mixtures 99

VIII The Bicycle Tire 120

IX The Pneum\atic Automobile Tire 128 •

X Transportation by Truck 149

XI Water-Proof Footwear and Clothing .... 168

XII Broadening the Field op Sport 187

XIII Power and Light 205

XIV Communication 217

XV Fighting Fire 235

XVI In the Service op Health 249

XVII Belting, Packing, and Hose 264

XVIII Rubber in the Home 283

XIX Gas-Masks 298

XX Balloons ....). 312

XXI The Future op Rubber 325 *"

Index 341

LIST OF ILLUSTRATIONS

WAOIVQ PAGB

Tapping a Rubber Tree Frontispiece

Sulphur Crystals Inside a Rubber Sheet 24

Difference Between Vulcanized and Unvulcanized Rubber . . 24

Washing Crude Rubber 32

Spreading Rubber Cement on Cloth 32

Weighing Out Compounds 32

Drying Rubber in Vacuum Dryer 49

Drying Rubber in Air Dryer 49

Various Weighed-Out Rubber Mixtures 61

Autobiography of Four Rubber Compounds 61

Mixing Rubber Compounds 62

Frictioning Cloth with Unvulcanized Rubber 52

Hancock's Pickle 62

Small Set of Laboratory Mills and Calenders 61

A Vulcanizing Press 61

A Rubber Testing Machine . « 61

A Rubber Plantation in Sumatra 64

Coagulation Tubs of the Plantation 64

Washing Coagulated Raw Rubber 64

Field Hands Gathering Cotton 68

Several Grades of Plantation and Wild Rubber 77

Map Showing Sources of Rubber and Cotton 81

Vulcanized Rubber Scrap 88

Reclaimed Automobile Tires 88

LIST OF ILLUSTRATIONS

Reclaimed Rubber Boots and Sboca 88

PhotomicrogTBpb o£ Barytes, Zinc Osides, Whiting and Carbon

Black 112

Fabric Tire Dieaected 129

Cord Tire Dissected 129

Building a Cord Tire 132

Tires Ready for the Vulcanizers 132

The Unvuleanized Tire in the Mold 141

Fillin g the Vuloanizers with the Molds 141

Effect of Pressure and Overloading on Tires 144

A Freight Track 161

One of the Trackless Trolleys 161

Parts of a Solid Tire 176

A Ladies' Slipper 176

A Rubber Shoe Made on the Amazon 176

The Soling Calender 1!)3

At the Make-up Table 193

Shoe Vulcanizing 193

Vulcanizing Hot Water Bottles 208 ■

Making Golf Balls 212

Wire Ready for the Vulcanizer 221

Covering Wire with Rubber Insulation 221

Braiding Wire with Cotton Thread 221

An Army Field Switchboard 225

A Modem Telephone Switchboard 225

Weaving Cotton Jacket of Pire Hose 240

Vulcanizing Cotton Rubber-lined Pire Hose 240

The Use of Rubber Hose at a Fire 248

Gloves Ready to Be Dipped 257

LIST OF ILLUSTRATIONS

VAOIHG PAOB

The Enclosed Dipping Machine 257-

Operators Rolling and Binding Gloves 257

Convey or Belt in Action 272

Yolcanizing a Convey or Belt 272

Applying Rubber Insulation on Garden Hose 280

Braiding Machines Making Garden Hose 280

Vulcanizing Garden Hose 280

Forcing the Jar Ring Compound Through a Tubing Machine . 289

Catting Jar Rings from Vulcanized Tube 289

Various Gas Masks and Helmets 304

United States Navy Type Blimp Dirigible 321

Spherical Balloon 321

Caquot Kite Balloon 321

Map of World Showing Registration of Motor Cars . . • 338

THE REIGN OF RUBBER

OHAPTEE I

THE EVOLUTION OF AN INDUSTRY

My purpose in writing this book is to confess to you
who employ rubber goods in any way, who take home
from shop or store the water-bottle, the garden-hose,
or the tire, something of the successes, failures, limi-
tations, and hopes of those whose lives are spent in
the creation of rubber products. Mystery has sur-
rounded rubber factories; secretiveness has been the
watchword; the methods of manufacture have been
little revealed.

But the old days of competitive reticence are past.
Because, perhaps, of the harmony engendered of the
World War, rubber men are more friendly with
each other. Exchange of ideas has been found
of mutual value. Research in each of the many
units of the rubber industry has developed to
the point where it may be said that there are few
secrets left. Thus the time has now come when the
makers should take their friends, the users of rubber
products, into their confidence.

I shall be most happy if from this effort may come
to you a clearer understanding of rubber commodities,

THE REIGN OF RUBBER

and a wanner sympathy toward the active partiw-
pants in this fundamental industry.

We live in a world of things and forces, in which
things are the visible evidences of ideas, and forces
are the means through which the creation of things
is accomplished. Down through the ages men have
struggled, thought, studied, tortured, and bled to
gain control of forces, that their children might have
things of comfort. The American loves his New
York, the EngUshman his London, the Frenchman his
Paris; for in them he finds the things which satisfy.
Late in the afternoon an observer upon the comer of
one of the crowded thoroughfares of these great cities
may find much of interest. The day is done. The
workers (are not we all such?) hasten to the streets —
the banker into the Umousine ; the derk, after a pur-
ohaBe or two, into the bus, the underground, or the sub-
way; the young bridegroom, with eager face — rushes
off to take advantage of the fastest transport avail-
able. Men go to the one place for which the things of
life are created — home. Each carries with him things
made in the industries which supply directly or in-
directly products rendering life happy and comfort-
able. So intent are we each day to leave business for
home that we rarely stop to delve into the reasons for
our possession of the necessary comforts of civiliza-
tion. The sources of our food, the origin of onr cloth-
ing, even the roofs over our heads, are taken ' for
granted. If the trolley fails to run. if the electric light
goes out, we blame the public service corporation. A
dead telephone may mean a late dinner; a blown-out
tire requires hard work, and we in these days are too

THE EVOLUTION OF AN INDUSTRY

little used to it. The luxuries of yesterday have be-
come the necessities of to-day, but they have come iuto
use too rapidly to permit a real acquaintance. The
things of rubber have become essential to the activi-
ties of life because of the valuable services they ren-
der. Without them our daily affairs would be strik-
ingly different.

The many enterprises which collectively compose
the vast rubber industry rose from small beginnings
in years so recent and into ramifications so numerous
that our modem world may truly be said to be under
the reign of rubber. The ruler of the realm is, id
democratic fashion, the servant, not the master. The
products serve, but do not dominate.

The substance used to produce these various articles
was made known to Europeans by the explorers of
the Americas. When Columbus landed in the West
Indies, he set men at work chopping trees. How our
forefathers did love to chop trees 1 Certain of these
trees oozed a white milk from the cut bark. Columbus
remarked upon this. Later, in 1525, Spaniards in
South America observed the natives playing with a
ball made of a black substance, left when this milk was
evaporated. Because of the wealth of unusual sub-
stances brought back to Europe by these explorers, it
is not singular, perhaps, that one of them, from the
weeping tree, should have afforded nothing of value
during more than two hundred years.

The South American Indians went on with their
ball play. Polities and wars absorbed the Europeans,
nntil during the later eighteenth century samples of
this weeping-tree product found their way into Eng-

THE BEIGM OF BUBBEB

liai VoWf die- En^Mbmmn has ever be^ a person
«f ■■■i.iiiiiliiiii, with zest to seardi oat the new and an-
BtaaL Therefore he itndied the new Anaiean pro-
daet in laboratoiy and ofiiee. With his eommereial
instiiiet, he pla««d jneees of it on sale. These
attracted the attentioD of I>r. Joseph Priestley. This
fanujOB efaemist, dergrman, teacher, anthor, who dis-
eoTered "depblogisticated air," — afterward named
oxygen, — wrote the following notice appended to the
preface of his "Familiar Introdnction to the Theory
and Practice of Perspective," printed in 1770:
"Since this work was printed off, I have seen a sub-
stance excellently adapted to the purpose of wiping
from paper the marks of a black-lead pencil. It most,
therefore, be of singnlar nse to those who practise
drawing. It is gold by Mr. Naime, Mathematical In-
stroment Maker, opposite the Boyal Exchange. He
sells a cubical piece of about half an inch for three
Hbilliiigs; and he says it will last several years." The
French had called this substance caoutchone, which
was as close as they could eome to caa o-chu, meaning
"weeping tree." Priestley did not name it, but the
men in the art shops christened it, in true colloquial
Knglish, "rubber" because it rubbed out pencil marks,
and "Indian" because of its origin in the West Indies.
Hut three shillings for a half of a cubic inch! It is
the highest known recorded price for raw rubber.
Would not our friends the owners of plantations rock
with joy could they charge that price to-day when a
bit leBs than two cubic inches brings but one cent?

Ideas arise from observation of objects. Some men
see, but do not gain thoughts or stimulus to imagina-

THE EVOLUTION OF AN INDUSTRY 7

tion from the things before them. Here was something
new — a firm, elastic substance from a country of
dreams. It was not soluble in water. Stories of cloth
waterproofed by the milk poured on and dried, had
filtered through to England and France. French chem-
ists undertook the first chemical study of the material ;
for, as in the case of all our modern rubber and in-
dustrial problems, research must ever precede produc-
tion. And the play of genius in bringing forth ideas
began. With characteristic energy, the English people
went forward most actively. Exactly where, when,
and how the first rubber factory of the world started
seems to be in some dispute, although it is stated that
in 1803 rubber thread for use in suspenders had been
invented by an Austrian in the suburbs of St. Denis,
near Paris.

Whether the purpose was the making of thread to
hold up the trousers of mailkind or the making of
water-proof garments, the first books on the rubber in-
dustry do not seem to agree. We do know that the
English were early the most successful manufacturers,
and that the first practical articles were clothing and
shoes. Many were the diflSculties, uncertain the re-
sults.

The names of Charles Mackintosh and Thomas Han-
cock are names ever to be remembered, because of
their extreme activity in building up the industry.
Discovering the solubility of rubber in various sol-
vents and producing air-tight materials by ** proofing*'
fabric, they made pillows, air mattresses, and life-pre-
servers. Although as early as 1791 the Englishman
Sanmel Peal had constructed waterproofed clothing

8 THE REIGN OF ETIBBER

with a single layer of fabric and a rubber layer on the
outside, he made no suecess. In 1823, however, Mack-
intosh overcame some of the difficulties. He invented
what was known as double-texture clothing, and the
"mackintosh" came into being. The mackintosh was
popular among men who rode on top of the English
coach. Things progressed swimmingly in England;
Mackintosh's factory grew. Hancock was an inde-
fatigable inventor. He went on with the making of
hose, bumpers, carriage tires, and a large number of
other products. Raincoats were shipped to America.
Rubber overshoes made on the Amazon River were
sent to Europe and America. The first rubber to be
imported into Boston was a rubber bottle from the
Amazon. S. C. Smith & Sons of New York were the
first firm in the business of dealing in rubber goods,
and the Roxbury India Rubber Co. of Roxbury, Massa-
chusetts, which was started in 1832 by John Haskina
and Edward M. Chaffee, was the first to manufacture
these rubber products in this country. Popular indeed
were the rubber products. A rubber boom had begun.

But there was a fly in the ointment; for this rub-
ber, though water-proof and moldable into many
shapes, possessed a basic fault. The rain-coats har-
dened in cold weather, so that the poor consumer
felt himself encased as in tin armor; in the summer
the rubber softened with the heat, melted, and fell
apart.

Many efforts were made to dry up the rubber and
prevent this stickiness and also to overcome the effect
of oil and grease, but without success. So completely
had rubber goods failed the American people because

THE EVOLUTION OP AN INDUSTRY 9

of warm summers and cold winters, that down to
about 1840 they were filled with dislike for anything
that related to * * gum elastic. ' ' People had become dis-
gusted and rightly so with goods that hardened like a
rock in winter and melted in summer. Even body
temperature melted the threads in suspenders, and
wearers of the celebrated mackintosh had to keep away
from a fire or find their rain-coats oozing from them.
The only reliable articles were Indian-made shoes
from the Amazon. Large quantities of clothing,
mail-bags, and other water-proof articles melted, de-
composed, and were returned. Therefore resentment
followed favor, and the rubber bubble burst.

Such conditions could not persist in connection
with so flexible a substance. Men may come and
companies go, but ideas grow in the minds of other
men, who form new companies to carry on. Charles
Goodyear, of New Haven, Connecticut, conceived it
possible to dry up this sticky, melting, freezing ma-
terial. Finally after years of effort, in 1839, he made
a far-reaching discovery. He heated a mixture of
sulphur, white lead, and raw rubber, and he observed
a marked change of properties. This erstwhile soft-
ish, doughy substance became firm, and strong; it no
longer hardened in cold weather or melted in the
summer.

Even in the face of trials, failures, and discourage-
ments, there are always a few men with vision enough
to see and to support a new idea. So a factory was
started in Springfield, Massachusetts, in 184J., to carry
out Goodyear 's idea. Here began the real rubber in-
dustry ; for vulcanization, as this process of heating

^V with 81

THE BEIGN OF RUBBER

with sulpbnr was termed, is the one essential process
even to-day. Withoat vulcanization, rubber as we
know it would not be possible.

A little later, in England, and hj wholly different
means of e-speriment, Thomas Hancock in 1843 dis-
covered the same characteristic displayed by sulphur
and rubber; thus about simnltaneously in England and
America the modern mannfacture of rubber goods be-
gan. A complete change had been brought alwnt by
Goodyear — a basic process discovered. How he did it
and what he did are left for a later chapter. Yet so
fundamental was this effect, and so intense his activ-
ity that for twenty-five years, from 1835, the history
of the rubber industrj- is little else than the i>ersonal
history of Charles Goodyear. An industry based
upon a far-reaching idea now took shape. These en-
terprises that men create measure their periods by
ideas and grow with mankind, provided the products
they offer render useful service. Rubber could now
capably serve; therefore growth was a natural conse-
quence.

It is strange how men strive to reap where others
sowed. I shall not here discuss Goodyear's troables.
Some men were pirates. His patent was infringed,
but finally sustained. Then came many companies.
Boots and shoes claimed almost exclusive attention of
iKveKtors and organisers for years.

The first rubber overshoes delivered into this cxmn-
try, in 1900, wer« made by the IndiuB on the banks (tf
th« Amaion River: hnl to-day Um old ^mcs have given
way to the new. aud wv are protected from the wvather
ilf "nibbers." Rubber boots har* we to be a i>arf

THE EVOLUTION OF AN INDUSTEY,

of the fisherman '3 outfit, and short ones are used by
lumbermen; the liveliness of our tennis matches is in
no small part due to the flexibility, lightness, and firm
grip of the rubber-soied tennis-shoe. Through vulcan-
ization, rain-eoats have changed from tin armor in
winter and the melted clothing in silmmer to a per-
manent, light, fiexible, water-proof, useful commodity,

In 1858 the trade in rubber products amounted to
between four and five million dollars annually, and
ten thousand men were engaged in the enterprise.
The Roxbury company was reincorporated ae the
Goodyear Manufacturing Co., later to become, as it
is still called, the Boston Belting Co.

There were many keen men of high purpose and
a few pirates. But some notable companies were
formed, and many of them are still producing. Three
great rubber manufacturing centers slowly developed.
There was the New England district where Goodyear
began, and the New Jersey centers where several foot-
wear factories began. A number of these companies
combined in 1892 to form the United States Rubber
Co. The district of Akron, Ohio, began in an equally
small way in 1870. The start resulted from the belief
in rubber of Dr. B. F. Goodrich and the enterprise
of the business men of the district.

Were I at this point to trace the history of rubber
goods development, the reader would observe a pro-
fusion of inventions offered to the Patent Office ; and,
characteristically, many of them were ahead of their
time. Ideas were written down, disclosed, or kept
secret; but no use was found for them until decades
later.

12 THE BEiaN OF RUBBER

Up to 1879, however, the industry strengthened; the
value of the products amounted in that year to
$25,310,000. It was truly an era of inventions and
business development, for this chemical change called
vulcanization had succeeded in making rubber suf-
ficiently permanent to warrant labor by inventive gen-
ius here and abroad in the creation of articles.

In this period were developed the conveyor belts,
which to-day are hundreds of feet long, serving to
carry ore from crushers to furnaces for a large num-
ber of different purposes. These, together with the
elevator belts, have become as essential a part of
mining operations as the crushing machinery used
in reducing ore to a state ready for furnaces. Rubber
has paralleled other inventions. To-day, in the trains
which carry us from point to point rapidly and safely,
we find rubber in the insulated wire for the lighting,
in the air brake, and in the steam-hose between the
cars themselves.

The "hose pipe" invented by Hancock in England to
replace the old leather hose for breweries has come
down to us through this creative stage, and now the
fire-hose has become a most essential development.
We might well stop to think what would happen when
fire-engines go shrieking down the street if there
were no vulcanized rubber in the hose so necessary in
the distribution of water to the conflagration. Fire
prevention is one thing; but when a fire is started, hose
that will not burst is an essential feature for rapid
extinction.

One need not run through a catalogue to show how
these early ideas have been carried down and improved

THE EVOLUTION OF AN INDUSTRY

for oar use ; that will be done with more detail in
chapters. I wish merely to anticipate and to mention,
farther, how large a part is played by rubber in sport,
with its base-balla, golf-balls, tennis-balls, and billiard
cnshions; how in the home, floor-coverings, jar rings,
garden-hose, fountain-pens, and other articles make
life more comfortable. Even in 1899, these articles
were so numerous that the industry had grown to the
statnre of $49,212,000 in the value of products.

In about that period began a noticeably rapid
change. Since nothing has quite so greatly stimulated
the imagination of business men as the possibilities of
the automobile, there is no period of the rubber indus-
try quite so filled with competition and with bubbles
that have been blown and burst as the period from 1899
to the present time.

When you drive your automobile into the mountains,
you give little attention to the part that rubber is play-
ing in making your trip interesting and comfortable.
If, however, a tire blows out and you are found fifteen
miles from the nearest service station, you consider
how necessary a commodity rubber has become at
least to that particular expedition.

The rubber-tire part of the industry is now a giant ;
it serves to carry ten million automobiles upon forty
million tires. Figures now astonish us, particularly
as we look back and mark the change after even this
short period of seventy-five years; for in 1914 the
value of the products of the rubber industry had
jumped to $300,994,000, and it produced in 1919 pro-
ducts to the value of $1,138,216,000, made by 475
factories.

In later ^^H
lention. '

16 THE EEIGN OF RUBBER

ber of these to be scientifically acted upon mechanically
to produce a mixture. It then forms those mechan-
ical mixtures into the approximate shape of a new
and useful commodity. This then is heated to bring
about the chemical change, vulcanization. As a re-
sult of vulcanization, each of these articles is capable
of service.

Since by common practice the word "rubber" is not
used in its original meaning, as describing the product
from a tree, there has arisen a confusion in terminol-
ogy. Most books and articles upon this subject have
begun the story with a description of the preparation
of the raw product, the early word for which techni-
cally came from the Indian term for the tree: caa,
meaning wood, and o-chu, meaning to weep ; hence, the
word "caoutchouc," It is probably the rapid growth
of caoutchouc products, called rubber before the
discovery of vulcanization, which has led to the con-
fusion ; for to-day we speak of rubber products which
have been vulcanized as "rubber." We also speak
of rubber as meaning the raw unvulcanized mate-
rial. Technically, therefore, "caoutchouc" means raw
rubber; and "rubber" to-day means vulcanized rub-
ber. Throughout this book the meaning will be evi-
dent in each case.

The rubber industry usually groups its products
under the names: mechanical rubber goods, tires, foot-
wear, clothing and proofed materials, druggists'
sundries, and hard rubber. These classes will not be
discussed, but rather the story will be written about
certain particular ones, representative of the classes
most frequently known and used. Each has a story

THE EVOLUTION OP AN INDUSTRY 17

of its own; each is interwoven with a romantic history
from the old days down to the present.

Since raw rubber exists in a variety of forms and
comes from a large nmnber of different places in the
world, since also its method of preparation and the
story of its growth are chapters by themselves, since,
likewise, vulcanization is the one fundamental proc-
ess necessary to an understanding of the indus-
try as it now exists, I shall not follow the order of
chronology, but plunge at once into a discussion of the
fundamental processes which have made the rubber
industry possible. This will give us a basis of un-
derstanding, and the series of short stories of different
rubber products will assume that the idea of vulcani-
zation is known to the reader.

CHAPTER n

PROBLEMS OF A PIONEER

Our eyes are holden that we cannot see the things that stare
ua in the face until the hour when the mind is ripened.

— Emerson.

The struggles of inventors in attempts so to change
the properties of raw rubber as to avoid hardening in
winter and softening in summer are truly the stories
of men who burned their fingers without realizing that
fire was the cause. Several of them were close to the
solution of the problem, and yet they passed it by.
Their failures make one believe that "our eyes are
holden that we cannot see" nntil discoveries may
properly coordinate with others.

A knife cut into the bark of certain evergreen tropi-
cal trees permits a milky sap to fiow. It looks like the
juice of a milkweed or a dandelion. When it dries,
there is left a brownish mass of a firm, tough substance.
This is the same stuff that came to Priestley's labo-
ratory and was called "Indian rubber." Frenchmen
brought it to Europe, where many enterprising Eng-
lishmen studied it and the great Faraday analyzed it.
Germans experimented. Thomas Hancock writes in
1856: *'It is a singular fact that although this sub-
stance had attracted the notice of chemists from the
earliest date of its importation into Europe, they

PROBLEMS OF A PIONEER

failed to discover any means of manufacturing it into |
solid masses or to facilitate its solution," That is a i
damaging arraignment of chemistry, but we must re-
member that the era of the chemical engineer had not
arrived. In those days the chemist was an analyst
whose chief aim in life was to find out what things
were made of, not to develop their uses.

The grand old man of rubber, Thomas Hancock,
owned a private laboratory. Not satisfied with a day 's
work, he studied at home by night. He dissolved rub-
ber in turpentine, and made many rubber articles.
Charles Mackintosh, in 1823, at Glasgow, invented a
process for spreading a rubber solution on two pieces
of fabric and bringing them together under pressure;
he thus created the double-texture, water-proof gar-
ment known even to-day as the mackintosh. Hancock
developed a machine for softening raw rubber. He
called it a "masticator," and his first experimental
machine held one pound. He invented iron molds ; and,
with a brick oven constructed by a bakery-oven builder,
he formed blocks of rubber under heat and pressure.
A little later, in 1822, he developed steam-heated ves-
sels and, several years after, a masticator capable of
holding two hundred pounds. It is fate that heat was
used by him, and that a little later sulphur played its
part, but that he did not connect the two. In his most
interesting description called "Personal Narrative of
the Origin and Progress of the Caoutchouc or India-
Rubber Manufacture in England," there were many
difficulties and handicaps mentioned.

Hancock, however, was a business man. Despite
the losses and the worries suffered through the effect

20 THE REIGN OF RUBBER

of lig^t in decomposing the caontchouc, he continued
to invent new uses for mbber and patented them. He
made artificial leather fay a combination of cotton and
other fibers in a rubber mixture. Much trouble was
occasioned when the tailors sewed rubberized gar-
ments together, for water crept through the holes
made by the needles. Then, too, because the grease in
the woolen cloth was absorbed into the raw rubber and
destroyed it, many were returned. Hancock was for-
tunate in living in England with its equable climate;
for the heat was not great in summer, or was the
cold severe in winter. Consequently, the numerous
products from his real inventive genius did not eeri-
onsly interrupt his profits.

I have wondered why he did not employ a research
laboratory. Although research in those days was not
conceived of as in our generation, he was so far ahead
of others that he might well have begun the practice.
He may have reasoned, though, in the way many of our
modem business men do, who seem to feel it advisable
to reduce the appropriation for research laboratories
during periods of depression. As a result, discoveries
have been delayed and opportunities lost because of
the lack of a little money expended for research at the
right time.

Hancock was on the verge of a great discovery, but
he lacked just the necessary something possessed by
another. While Hancock worked in England, there
was some activity in America. In 1833, in consequence
of goods returned because they had melted in the heat
of summer, the Roxbury India Rubber Co. was on the
verge of dissolution. The firm had sent out products

PEOBLEMS OF A PIONEER

with nothing done to prove their value except the test '
of actual service ; it has taken years to develop in the ■
minds of men the fact that in fairness to the eonsumer
tests of quality should precede sale. In the hot ;
rains of August, rain-coats oozed rubber, while mail-
bags fell apart, and letters were scattered. During
zero weather the shoes sent from the Amazon became
wooden, like the "klomps" of Holland. An unreliable
article was the suspender in those days; perhaps that
is why Americans came to prefer the belt to "gal-
luses."

One day Charles Goodyear of New Haven, Connec-
ticut, a man of thirty-three, passed by the New York
store of the Boxbury company. He was not a busi-
ness man, for he had failed in the hardware and farm
implement business. He saw some life preservers.
Because he could not help inventing, he designed a new
one and returned a few months later to submit his
sample to the clerk in the store. The clerk, wishing
to do the enterprising Goodyear a service, confided to
him the troubles of the Eoxbury company. Placing
a difficulty in the way of a genius creates the stimulus
that ever has brought forth latent activity. Goodyear
set to work. Cast into prison for debt, he shaped
small test samples of raw rubber with a rolling-pin
from the family kitchen. He mixed rubber with lamp-
black, magnesia, and turpentine. With true research
spirit, he submitted each of his mixtures to a weather-
ing test in the open air.

A "presentiment of the future" spurred him on,
until he became shabby and emaciated. His hands and
clothing seemed to be covered continually with India

ItHIR KKiaN OP RUBBER

'—'.J., utd kMAH.v of Ills friends tried to dissuade him
I ii thill (la- India rubber business was now
XI iliiti time some one in New York was
, ..^,1 i.i..» ^v- miglit recognize Mr. Goodyear. The re-
l>lv ^,a«; "U yim meet a man who has an an India
tunbt'i' 04^ Htuuk, coat, vest, and shoes, with an India
riiWK-'i' purat) without a cent of money in it, that is he."
'fivi-' t'lii-'udb who bad backed him were ruined in the
li^iiii! of ia36-37. By treating caoutchouc with nitric
a,oid, ho uea rly suffocated himself in 1837. But
uotliiug i'.ati slop genius.

Whou the officials of the Rosbury company offered
to help lura with the use of the machinery at their
plaat, h« removed to Roxbury. Although his inven-
tive genius was used in the production of better ar-
tioles, the thought of using sulphur did not occur un-
til 1H3H, when he became acquainted with Nathaniel
Hayward of Woburn, Massachusetts, who was the
foreman of the factory of a rubber company that had
juBt failed. Hayward was a practical man. He had
approached the discovery of vulcanization, but he had
not found it. His contribution to Goodyear was a
process for partly hardening rubber by spreading a
umall quantity of sulphur over the surface of the raw
rubher article. Then the mixture was put in the sun
to dry. His patent, wlilch was taken out in 1839, was
purchased by Goodyear; and Goodyear used it in the
manufacture of life-preservers.

Goodyear was approaching the solution of the proh-
lem that so far had seemed the doom of the rubber
industry. Several different tales have been told, each
of which sets forth the accidental nature of his great

PROBLEMS OF A PIONEER

discovery. Possibly the best way to bring to light the
truth is to let Goodyear himself explain; this 1
in that rare old book "Gum Elastic," published in
1853. I shall not use his exact words throughout, but
I shall quote hira sufficiently to indicate the creative-
ness of his mind and the research character of his ef-
forts.

He was on a visit to the factory at Woburn, where
he had met Hayward. At the dwelling there where
Goodyear resided, he made some experiments to as-
certain the effect of heat upon the same compound
that had decomposed in the mail-bags and other ar-
ticles. He was surprised to find that the specimens,
being carelessly brought in contact with a hot stove,
charred like leather. He, however, directly inferred
that if the process of charring could be stopped at the
right point, it might divest the gum of its natural ad-
hesiveness throughout, which would make it better
than the native gam. He was further convinced of
the correctness of this inference by finding that India
rubber could not be melted by boiling in sulphur at
any heat ever so great, but always charred.

Other trials were made in which similar fabrics
were heated before an open fire; and the same effect,
that of charring, followed. "There were further and
very satisfactory indications of ultimate success in
producing the desired results, as upon the edge of
the charred portions of the fabric there appeared a line
or border that was not charred but perfectly cured."
With characteristic ability, he then tried other methods
of heating, including steam. That this discovery of
curing rubber was no accident, he himself makes

THE EEIGN OF RUBBER

evident when he says: "While the inventor admits
that these discoveries were not the result of scientific
chemical investigations, he is not willing to admit that
they were the result of what is commonly termed ac-
cident ; he claims them to be the ^esnlt of the closest
application and observation."

The discovery of rubber vulcanization was made in
January, 1839. Possibly the season was fortunate, be-
cause of the ease of performing heat tests near stoves
on the inside and because of the severe cold for the
weathering tests outside. But Goodyear had by no
means finished ; for after his years of want and misery,
discouragement and lack of support, he then went on
to the next stage, that of convincing people of the value
of his invention and of protecting it from the aggres-
sions of those who now claimed that it was not his
invention at all.

Dr. Baekeland has well written: "I believe it was
George Westinghouse who reminded us that every suc-
cessful invention passes through three stages; The
first, when it is said : ' Such a thing is absurd or im-
possible.' The second stage, after the patent de- .
scriptions have become public and have given others
the means to imitate and try to find loopholes in the
patent claims, begins when it is said: 'The thing is
not new.' And finally, after the usefulness of the in-
vention has become so obvious and the details con-
nected therewith have penetrated through the hard
skulls of the laggards, then it sounds : ' There is no
invention at all.' "

So human inertia held back Goodyear: it was 1841
before he convinced men with money, William Rider

Courtesy of The B. F. Goodrich Co.

TemperiLture DeEreea F

PROBLEMS OF A PIONEER

and William DeForest of New York, of the value of hia
discovery. Shortly thereafter the factory from which
the rubber industry in this country has sprung was
started in Springfield, Massachusetts, Ever secre-
tive, Goodyear was afraid of losing his rights; and
while he obtained protection under a deposition of dis-
covery in December, 1841, it was not until June, 1844,
that the specification for his original patent was
granted by the Patent Office at Washington.

Meanwhile, he had sent to England a representative
to learn if the secret could be sold to the rubber manu-
facturers there.

Thomas Hancock here takes up the story, in which
he describes how in the eariy-ptrrt of the autumn of
1842 an assistant of his riaTuedBfdekeifen showed him
some sample bits of rubber that had: been brought
over by a person from America; It ;was said that
cold would not stiffea-them and-that "they were not
much affected by solvents, heat, or oils. But busi-
ness men feared the idea of an inventor: the Mackin-
tosh company told the agent that, as he could give no
information, they could not judge of the merits of the
invention and they were afraid that the product might
not be capable of manufacture on a large scale, with-
out a fresh outlay of money. Meanwhile, Broekedon,
being interested in stoppers for beer-barrels, was im-
pressed with the suggestion ; he gave samples to Han-
cock, who at that very time was engaged in a study of
methods by which rubber goods could be divested of
their adhesiveness and made more permanent.

Hancock took the usual industrial competitive point
of view and set to work "to match the competitor's

THE BmOX OF BUBBER

samples." Thoe« of my readers who are chemiBts
ID the robber baeiness, will recognize this as one of
the daily demands made open them; they may be
eheered in realizing how this system has been handed
down from the early days. We mbber men are vic-
tims of oar circumstanceB; every one of us pulls, bites,
and smells new samples. Hancock was no exception.
He foand in the samples strength, resistance to heat
and cold, and a slight odor of snlphur. To solve the
secret of the new compound, he heated raw rubber in
molten sulphur. For a second time the sulphur-
cHoiitchouc combination was effected by heat, Han-
cock promptly patented his discovery in England in
November, 1843. His assistant, Brockedon, termed
the process "vulcanization." Thus, an American dis-
covered the process; an Englishman named it; all the
world has come to use it.

Goodyear had made the short indispensable step in
rubber manufacture; yet his discovery was the ob-
jective of pirates, infringers, and guerrilla warfare.
His claims, however, were sustained by litigation;
Daiiiol Webster was his counsel, and Rufus Choate
was the lawyer for the defendant. These legal con-
troversies resulted in establishing clearly Goodyear's
priority and led to the extension of his patent for
seven years from June, 185S. As Judge Grier, in giv-
ing judgment in 1864, stated: "Envy robs him of the
honor, while speculators, swindlers, and pirates, rob
hira of the profits. Every unsuccessful experimenter
who (lid, or did not, come very near making the dis-
covery, now claims it. . . . Every man who has made
(>xporiments with India Rubber, sulphur, lead, or any

PROBLEMS OF A PIONEEE

27 ^H
Btove or ^^^

other substance; who has heated them in a stove
furnace ; who has annoyed his family and his neigh-
bors with sulphurous gas; who has set up a rubber
factory and failed; who has made India Rubber
that no one would buy, or if bought, were returned as
worthless, are now paraded forth as the inventors and
discoverers of vulcanized India Rubber. . . . We are
of the opinion, that the defendant has most signally
failed in the attempt to show that himself, or any other
person, discovered and perfected the process of manu-
facturing vulcanized India Rubber before Charles
Gtoodyear."

Poor man, he died in New York in 1860 with debts
of more than $191,000. A brilliant mind, a persis-
tent worker he was, but a life of trouble was his. He
was not a money-maker but an investigator. He never
belonged to any of the so-called "Goodyear compa-
nies," or has any member of the Goodyear family
since his death ever been in the rubber business. The
name became a trademark. When his estate was fin-
ally settled, the debts were paid and a comfortable
fortune was left to his family. But, despite that,
there ended pathetically one of the greatest names in
inventive history. Emerson has written: "Every
action is measured by the depth of the sentiments from
which it is produced." Qoodyear's persistence and
his ability, the depth of his driving force, gave to the
world the basis from which has sprung this tremen-
dous industrial development of rubber. Thomas Han-
cock, with that fairness so characteristic of the Eng-
IJBh , acknowledged him to be the discoverer.

THE EEIGN OF EUBBEB

only discovered the fact of the rnhber-salphar union
with heat, hot he developed the range of temperatnres
from 212° to 350° Fahrenheit, within which vulcan-
ization can occur. Further, he observed the necessity
for removing the material at the end of a suitable
time. And to-day the properties of rubber obtained
from vulcanization depend upon the amount of sul-
phur and other substances in the mixture, the temper-
ature at which the mixture is heated, and the time
during which it remains under the influence of heat.
The whole of rubber compounding practice, which will
be discussed in another chapter, is purely one of
adapting different materials, different amounts, dif-
ferent times, and different temperatures to accomplish
definitely sought properties.

Sulphur is as important to the rubber industry as
rubber. For while other substances have been found
which, adding themselves to rubber, vulcanize it, sul-
phur is the only one that combines cheapness with the
ability to produce high qualities in the resultant vul-
canized mixtures.

CHAPTER III

FUNDAMENTAL METHODS AND MACHINERY

The entire rubber industry can be summed up thus :
It is the business of making and vulcanizing mixtures
the chief ingredient of which is raw rubber. Cotton
fabric is necessary to give strength and shape to par-
ticular articles, but there would be no rubber goods
without rubber mixtures. Mechanical processes serve
to form the articles with speed and precision, but mix-
ing is the fundamental process. Even were rubber
and sulphur the only substances employed, it would be
necessary to have machinery of some kind in order to
incorporate this dry powder, sulphur, into the tough
raw rubber.

Rubber is a plastic; it is a body that when pushed
does not break, but yields slowly. If a block of raw
rubber is placed upon a table under a heavy weight,
it gradually settles to a position of balance; that is,
it settles until the resisting forces of the rubber coun-
terbalance the downward pressure of the weight.

This plastic nature of rubber makes it possible for
us to mix substances into it. The earliest known
machine used in any type of rubber manufacture was
a miser, called a "pickle" by its inventor, Thomas
Hancock. In his early days, about 1820, Hancock was
engaged in the matter of elastic fastenings for gar-
ments. He made springy stockings and elastic gloves.

THE BEIGN OF EUBBER

n the course of his work, he accumulated considerable
quantities of scraps. He also made elastic bands of
rubber by cutting up small thin bottles imported from
South America. These bottles had been made by
evaporation of the latex upon forms. With the
cuttings to save, Hancock cast about for some means of
forming them into uniform pieces. His first step was
to procure a hollow punch an inch square and to cut
out squares of rubber. He then tried pressing the
pieces with a plunger in an iron mold. These ideas
seeming not to succeed, he invented the first mixing
machine.

This machine was simply a hollow, round box of
wood, with a crank for a handle and spikes upon a
cylinder revolving between spikes in the wood about it.
By these means, he was able to tear the rubber into
small threads. If the cuttings were previously heated
and the action was continued long enough, they
gradually worked up into a homogeneous mass. See-
ing the success of his experiment he went to a firm of
machinery builders in England and had them make
for him an iron machine of the same character. The
improved apparatus he kept a deep secret until about
1832. Continuously the active Hancock improved and
developed this hollow cylinder affair, making it larger
and larger and driving it by horse-power. The earlier
name "pickle" was shortly changed to the more ex-
pressive designation of masticator or masticating
machine. The old pickle was slow. Hancock had one
made to hold 180 to 200 pounds, but it did not mix dry
powders and raw rubber with speed and accuracy.
But let us go on to the processes of the modem

METHODS AND MACHINERY

rubber factory and follow them along. To-day
rubber comes chiefly from plantations, clean and ready
for the first step in the manufacturing operation.
There are, though, scraps from the trees and "wild"
rubber from South America. These grades are dirty
and wet. Therefore each factory needs a wash-room
where the dirty raw rubber may be cleaned. The
clean raw rubber needs only inspection. As each sheet
is separated from the other sheets in the box, it is
easily brushed free from any chips or foreign matter
that may have been picked up in the course of trans-
portation.

Because the wash-room employs heavy machines,
hot and cold water, and steam, it is a sloppy, wet, dirty
department. The workmen, in rubber boots and
aprons, throw the solid bales or lumps of crude rubber
into tanks, sUghtly to soften it with warm water.
Then pulling apart the sheets of baled plantation rub-
ber, they pass them between the two rolls of the wash-
ing machine known as a cracker. The two steel rolls,
placed horizontally and parallel to each other, are cor-
rugated; and they, to loosen the dirt, grind the sheets
in contact with water. The washer, the next machine,
has smaller corrugations cut into the rolls, which bite
into the rubber and bring to the surface any foreign
particles, which are washed out in the stream of water
that constantly runs upon the mill. A step at a time,
the sheet is corrugated more and more finely, or
"creped," while new surfaces are exposed to the wash-
ing action.

There are several different kinds of washers, such
as two-roll washers and three-roll washers, inclosed

ly raw Jl

I ronHu '

THE EEIGN OF RUBBER

"Washers, tub washers, beater washers, and varioi

others. But let us go along from the washing room to
the next step, which consists in drying the rubber.

I Before any other substance can be mixed with rubber,

I it must be dry.

I The wet sheets, which are probably one sixteenth to
one eighth of an inch thick, about twenty-four inches
wide, and vary in length from six to fifteen feet,
are taken on trucks to the dry room. Several different
methods of drying are used. In the old days, these
sheets of rough-surfaced rubber were simply hung up
in a room and allowed to dry over a period of time
varying from two to six weeks, since raw rubber does
not lose its water so rapidly as cotton cloth. They
were never hung in the sunlight as we do clothing. In
bright light, raw rubber oxidizes and spoils ; therefore
the dry room must be dark and free from smoke and
dust. Because inventors dislike any six-weeks long
process, to speed up drying they forced the air in by
fans and carried it out by exhaust. Six weeks dwin-
dled to one.

Then came a German invention, the vacuum cham-
ber, into America, with still more rapid but safe drying.
The vacuum apparatus is nothing but a metal chamber
with hollow steam-heated shelves in it. The rubber is
laid upon trays, slid in upon these shelves, and the
door closed. By means of a powerful vacuum pump
the air is exhausted. Steam is turned into the plates,
and the rubber is heated to a much higher temperature
than that used in the air drying rooms. In the
presence of a vacuum, though, the danger of de-
terioration by oxygen is avoided. The temperature

Courttsy of The fl. F. (ipodrich Co.

r-s^-«

iTUfy of Tht- Fjrt-:loni: Tir^' & Rubber Co.

METHODS AND MACHINERY

may now be raised considerably higher; and since
water evaporates more rapidly in a vacuum than in the
open air, the time required to remove the water from
the rubber is reduced to two or three hours.

But the vacnum drier did not seem wholly satia-
factory for all types and kinds of rubber and for all
purposes. In recent years, there has been another
method that has entered into rubber manufacture, that
of drying in the presence of moist air. It seems a bit
singular to dry anything in wet air. Nevertheless, the
method, with several systems of rooms in which rubber
is placed on racks or trays, has been successfully used.
The raw rubber dries in twenty-four hours. Really
the air is only relatively wet. The water passes to the
air because the air is drier.

Many advocates of each!of these systems qf drying
are found in the nibber industry. Each system is
valuable for different types and grades of rubber
to be used for various purposes. We are, however,
here interested more in the fact that after the rubber
comes out of the sloppy wash-room, it is dried before
it goes into the next stage in the process of its manu-
facture.

Now our rubber, whether of one grade or several, is
ready for the weighing-out of the mixture. Here we
step into the holy of holies of the rubber factory.
From the beginning of the industry, rubber plants have
carefully guarded the composition of their mixtures;
they are the recipes of the business. Each one of
Ihem is made for a particular purpose. Since every
rubber factory is convinced that its own formulas are
better than the formulas of any other, each guards its

THE REIGN OF BUBBEE

recipes as something sacred. So carefiil are they,
that the recipe, as it issues from the faboratory to this
weighing-out or compounding room, must needs be
divided up into different parts by the chief compounder
or confidential man. The grades and quality of rubber
to be used are written on one card, the dry pigments on
another, the reclaimed rubbers on still another, and
the sulphur on a last one.

In the compounding room the final work of the
chemists really comes into play. In this part of the
factory great accuracy is required. To be sure, if the
manufacturer happens to be a rubber man of the old
school, he may call his chemist into the private oflBce
and tell him how in the early days there were no
chemigts and no laboratories. He may even try to
convince him that powders were measured by the
bucket and rubber by the yardstick. But because thii
demands made upon rubber goods have become more
and more exact, greater accuracy is required at the
present time.

Care is necessary in preparing these various sub-
stances other than crude rubber. The dry pigments
must be sifted through fine silk screens free from
foreign ingredients. The coarse particles, the chips
from the bales, or any other accidental substances are
thrown into the scrap-heap. The compounding room
is one of the places in the rubber factory where purity
of substance is accomplished. Obviously, there would
be tremendous irregularities in rubber composition
were the scales not exact upon which these substances
are weighed. At regular intervals, standard weights
are taken about the compounding room; and each set

METHODS AND MACHINERY

;en some ^^H
'eigh the ^

of scales is adjusted. Although there have been g
efforts made to develop automatic scales to weigh t
right quantity of a single substance for each of a large
number of batches, up to the present time none of them
seems to have come into sufficient use to warrant its
being considered as accurate or reliable.

In the best of the compound rooms, the powders,
after sifting, are automatically dropped through the
floor into metal hoppers, each containing its own
particular pigment. From these bins, which are
placed side by side, the operator weighs out the proper
ingredients. Conveyor systems are used for handling
the boxes, so that the pigment boxes and the rubber
boxes move systematically from one end of the room
to the other, each receiving the correct quantity of the
right substances. When these various substances are
accurately weighed and placed in their respective
boxes, they are conveyed down to the mixing room, or,
as the rubber man terms it, the mill-room.

We speak of the masticator, the mixer, or the mill.
By common consent, a rubber mill is considered to be
that particular piece of machinery upon which the va-
rious ingredients of a compound are mixed together
in form for the next step in the operation. Ed win
M. Chaffee, one of the pioneers of the American rub-
ber industry and a co-worker with Charles Goodyear,
was the inventor, in 1836, of the first iron-roll, steam-
heated rubber mixer. It was a different machine from
Hancock's, for Hancock kept his rubber inside a cham-
ber. Chaffee had his rnbber outside, but in such
fashion that it was compressed between two
rollers. From the original Chaffee mixer to the mod-

THE EEIGN OF RUBBER

ern mixing machine is not a great step in fundamen-
tal principle, and Chaffee may be considered the
father of rubber factory machinery.

Of different sizes, the largest of these machines to-
day consists of two mixing rolls, twenty-four inches
in diameter and eighty-four inches long, set in a heavy
frame, and made from either chilled or dry sand iron.
One roll has a driving gear operated by a pinion on
the shaft underneath, on one side. On the other end
of the drive-roll is a gear which meshes into another
gear on the end of the front roll. These gears are of
different sizes, to give friction or different speeds to
the rolls, eo that there ia a wiping action upon the
rubber as it passes between them. This wiping action
seems to be efficient in forcing the dry powders into the
plastic rubber. Set beneath each of the mixers ia a
metal pan ; for when the rubber is being masticated
and mixed, not all of the dry pigments remain on top
or go immediately into the rubber. A good deal falls
through into the pan; and the operator, with a brush
and a shovel, gathers this up and shovels it from time
to time to the top of the mill.

Let us go down into the mixing room and see h(Jw
a batch of material is mixed. Stand in front of this
piece of machinery. The speed of the rollers is not
high, — only a matter of fifteen to twenty revolutions
a minute, — but one gets the impression of great power.
Our operator, standing in front of his mill, picks the
rubber ont of the boxes; and, placing it in position on
the upper side of the moving rolls, pushes it so that
it is caught and drawn in between them. With a
powerful action, with grinding and screeching, with

METHODS AND MACHINEEY

the bursting of little blisters as they form, the ]
robber is carried between these two rolls and broken
up into various large chunks. An automatic meehan- '
ism known as an "apron" brings the rubber that
falls between the rolls up again to the top, where the
operator pushes it once more over into the space be-
tween them. He is protected against accident by an
automatic tripper. If he leans his hand against the
tripper, the motor will he disconnected from the mill
and the resistance of the several mills on the same
shaft will cause them all to stop. So our workman,
without danger, protected by the best of safety de-
vices, continues to see that the tough, cold rubber is ,
sent back through the rolls.

Yon observe how the rubber gradually softens; it
begins to smooth out in spots. The noise and creaking
of it subsides, until, after ten or twelve minutes, it ia
smooth and clings to one of the rolls sufficiently so
that it goes around in the form of a sheet the thick-
ness of the space between the rolls, usually about three
quarters of an inch. A little excess of rubber ,known
as a "bank" stands on the top between the rollers.

Then the rubber is masticated. It has been softened
by the friction developed by the two rolls running at
different speeds, by the heat generated, and by the
mechanical working. When it is thus softened, it is
ready to have the dry pigments added. The operator
now shovels the dry pigments from the compound box,
in which the mixture was brought down from the com-
pounding room, upon the upper parts of the rolls.
Some day all rubber mixing apparatus will be equipped
with automatic mixers. The workman shovels the

THE BEIGN OF BUBBEE

other substances upon the mbber, without knowing
what they are, where they came from, or their quan-
tities. Quickly the masticated rafaber, as it comes
aroond, catches up a coat of dry pigments. Since it
takes a little time for the mbber to absorb these aub-
stances, much of the pigments slips through and is not
pressed into the rubber.

Rnbber is a peculiar material; it cannot be quickly
forced as machines can force brass or steel ; it yields,
and then returns to its original position. It seems to
have a temperament; it can be guided, but only slowly
driven. Therefore the workman shovels on the pig-
ments at about the rate that the rubber wishes to eat
them up. The sheet on the rollers looks streaked and
irregular. After five or ten minutes more have
elapsed, though, all the dry pigments will have die-
appeared ; but the rubber still seems grainy, like wood.
At this point it is probably in its most critical state,
so far as uniformity is concerned. If this batch
in its present condition were to be taken from the mill,
it could not yield a product of good quality. There
would be more powder in one part of it than another.
The sulphur would probably be concentrated at
one end.

The workman is obliged now to perform the final
but most necessary operation, that of true mixing,
which he does by what we call "cutting back and
forth." With a sharp knife and the skill born of ex-
perience, he cuts his rotating, thick, slow-moving sheet
of rubber, so that a long strip probably a foot wide is
removed from one end of the roll. This strip he
quickly throws over across the roll; thus he transfers

METHODS AND MACHINERY

a portion of the rubber from one end over to tfac other
end. When that has passed around, he cuts from the
other end a similar long strip and throws it back in the
opposite direction. In this way, different parts of the
batch are removed from the places where they were
and are put in contact with rubber in other parts of
the batch.

The operator is now a busy man, for he cuts and
throws these big ribbons over against the sheet. Back
and forth, back and forth, on a large-scale operation,
he acts as the druggist when he mixes hia pill powders,
or the housewife when she mixes bread; he inter-
mingles all parts of the batch. The rubber is now
soft and hot. Temperatures of 180° to 200° Faren-
heit are generated by the heat of friction, despite the
fact that a stream of cold water is forced into the
hollow cavity of these rolls for the express purpose of
regulating the temperature of the mixture. So high
is the heat of friction that if the rolls were not cooled,
the composition would partly vulcanize while mixing.
We call this "semi-vulcanization" or "scorching."
Because the mill-room operators must constantly
guard against scorching, cold water has come to be a
necessity in the rubber industry. I do not mean ice-
cold water. That would be too cold. In the econom-
ies of the rubber industry, the location of a rubber
factory where good, cool, water, and plenty of it, is
found, is as fundamental as that of a location upon a
railroad.

The technique of mixing is varied ; it is one of the
skilled operations of the rubber industry, compositions
of different character requiring variation In handling ;

; higher
Uittvtaf o&tsra. It is mtens&ng to those who f ol-
r Ike d^jub of the hisbvj of the robber industry to
e bow vitfam the last few years inclosed mising
wtadaae* hsve graduaSfy eame back into nse. The
firat Hancock maatieBtor was an internal machine,
and the Chaffee was made on the external principle.
In a limited way, we now again mis in chambers by
the internal action of the rotating parts; this action
softens the rabber by working it against the side of
tbe shell that indoees it.

When onr worfcman is finally satisfied that the rob-
ber is thoronghly mixed with the pigments, his next
utep is to remove it from the mixing machine. This
he does by catting a large sheet from the masticator
as it rotates in front of him; he then throws it by a
qnick movement npon a cooling-table. Here it is al-
lowed to stand for an honr or two until it is cooled
saflSdently to avoid a scorching tendency. From this
place, it is transported to the storage room, or into
the factory where the next operation is performed.

It we take a trip aroimd the plant, we logically go
from the mixing room to the department where the
rubber is made ready for the forming operation. In
the old days, the mixed rubber was dissolved and
then applied upon fabric by means of a spreading
machine. This machine was constructed to permit a
sheet of cloth to pass over a rotating cylinder, above
which hung a flat metal bar called a knife or doctor
blade. The blade was accurately adjustable. So close
could it be set to the fabric that it permitted only a thin
film of solution to pass between it and the fabric.

METHODS AND MACHINERY 41

Thus a thin layer of rubber cement could be applied to
cloth.

One day in 1835, Mr. Chaffee went to the diisectors
of the Roxbury company, saying he could save them
the expense of the solvent that they had been using
by the old process, which, by the way, cost them about
fifty thousand dollars a year. He was instructed to
build the necessary machinery. The invention of the
calender machine resulted.

His coating machine was called the ** monster** or
the ** mammoth,'* on account of its dimensions. It
weighed about thirty tons, and was finished toward the
end of the year 1836 at a cost of thirty thousand dol-
lars. The Roxbury India Rubber factory purchased
from Mr. Chaffee his entire interest in the ** monster.**
But during the month of October, 1843, the huge ma-
chine was sold at a public auction for only $525 to John
Hasldns, who at the same time purchased a patent on
it for $1.50! During the year following, 1844, Has-
kins disposed of the ** monster*^ to Charles Goodyear,
who later transferred it to the Naugatuck India Rub-
ber Co.

A calender is simply a machine with three or more
heavy steel rolls set parallel to each other, in such a
way that when the soft, warm, unvulcanized rubber
mixture is fed against the space between two of the
rolls it will be forced between them in a thin sheet.
This is called a sheeting calender. Likewise, when it
is desired to apply rubber to cloth, cloth is drawn be-
tween the rolls, which are separated far enough so as
in no way to crush the fabric, and which push the soft
rubber into and around the threads. This is termed

THE REIGN OF RUBBER

a "friction calender," and the operation "friction-
ing." In the parlance of the trade, we speak of the
compound as the "friction" and the cloth as "frie-
tioned fabric." In other machines, the cloth, after
f rietioning, can have a coat or layer of ruhber applied
upon it. For tire fabric purposes, we are accustomed
to speak of "friction and coated fabric," or "friction
and skin coat."

If in the calender room we stand in front of one of
these machines, which are from seven to ten feet high,
we find masses of rubber compound, as they run from
the rolls, taking the shape of sheets. To keep them
from sticking to each other, they are wound up with
cloth or "liners" to separate thean. The sheets issue
from the machines at considerable speed, and are
whirled into roUs, which are carried to the various
other parts of the factory on hand-pushed or electric
trucks.

Many other machines are employed to make particu-
lar articles in the rubber industry, but those described
are the essential ones.

The manufacture of rubber goods may be likened
to a tree. Thousands of materials — raw rubber,
powders, sulphur — are the roots. These are combined
in the trunk, through a few basic methods. The miU-
room, where mixing is done ; the calender room, where
the first process of forming is accomplished, are the
steps essential to manufacture. The final step of
forming and, last of all, vulcanization, are carried on
in the several divisions of the factory within which
the special articles are produced. They are the
branches of our tree.

METHODS AND MACHINERY 43

Bubber mixtures are the basic materials ; the chem-
ist formulates them; cotton cloth and these mixtures
are put together in forms and shapes by the design-
ing engineer who creates articles; and, to manufacture
them expeditiously and uniformly, the inventor and
production engineer must invent and use many kinds
of machinery. The rubber industry, therefore, stands
on three legs ; the mixture, the design, and the machine
—each essential.

CHAPTER IV

THE RUBBER MAN'S COOK-BOOK

Oh, I am a cook and a captain bold,

And the mate of the Nancy brig,
And a bo 'sun tight, and a midshipmite,

And the crew of the captain 'g gig.

—Gilbert: "The Yarn of the Nancy Bell."

The old-fashioned rubber BUperintendent was a ver-
satile chap. From dawn on, there came to him for de-
cision essentially all the manifold problems of the
rubber factory. Personally he selected the laboring
men; he was the power engineer, and if the coal was
bad, it was his duty to keep the plant running. He fig-
ured costs and made prices. A chemist also, he wrote
the formulas or recipes for the various mixtures used
in the goods manfactured. He was even the first-aid
doctor; since in the early days machinery was not
surrounded by the safeguards that we find to-day, and
many a man whose hand was caught in the mixing
mill was carried to the superintendent's office for
first-aid dressing. In many cases, he was a salesman ;
and he certainly was the production driver. As both
an inventor and a promoter, he labored. Truly those
were strenuous days for the superintendent.

I once talked to one of those men, long since retired
from active participation in rubber factory work. He

P' ^
THE RUBBEE MAN'S COOK-BOOK 45 ^H
how the mixtures of rubber, which we call by ^^H

t}i(» Tianlp (if "("fimnniind " w/pro afiirliofl in hia nffii^p '

the name of "compound," were studied in his office.
By means of a little piece cut from a sheet with a pair
of shears, he tested the quality. This fragment he
twisted, pulled, and worked in his fingers. Finally al-
lowing it to come to rest, he examined it, to see how
much longer it was than the original piece from which
it was cut. The ease of pulling, the "feel," and the
additional length were prime factors in determining
the quality of a particular mixture. Even teeth were
trained to bite pieces from a specimen, the resistance
to the bite being a measure of its strength. A testing
laboratory was ever with him in the form of fingers
and teeth.

Those old formulas were clouded with secrecy. In
the compounding room were employed only most re-
liable men, known for honesty and loyalty. A recipe
was a great secret of master importance. Before long,
however, ambitious youths came to realize that qual-
ity as produced by good formulas was the basic prin-
ciple on which the success of a given rubber plant was
built. Therefore many of them left, taking with them
the secrets ; and competition rapidly grew.

To-day, with the coming of the chemist, a different
tone has been given the industry; no longer does the
rule of thumb method apply. No longer is it neces-
sary for competing institutions to worry much about
the compositions used in the factories of each other.
There has come in these recent years a fuller under-
standing of why various materials act in particular
ways when used in rubber mixtures. The chemist,
the physicist, and the engineer have brought real

THE BEI6X OF BUBBEB

fcMHrie^e into rubber makiii^. To promote such
fca w riedl g i^ ead of the larger isbber eompames has
offlguiieil laboT^Umea, in wbieb highly trained chem-
Mla •Cady new materials and, as a banc function of
tmA wtady^, learn bow eaA matnial performs in a
rvbber iiiixtiir& There are testing laboratories, too,
wbne eadi rabber composition mar be stadied and
vfiere eadi new prodnct may be tested in terms of
aetnal serrice.

The mbber that yon see in the form of a mbber
band, the heel that yoa wear npon your shoe, or the
tread of a pneranatic tire, is not jnst a simple vulcan-
ized mixture of rubber and sulphur or is it so simple
a composition as the combination of rubber, sulphur,
and white lead used by Goodyear. The compositions
are much more complicated than they formerly were.
In the course of the evolntion of this industry has come
a revised point of view, bo that to-day each substance
used in a mixture is there for a particnlar purpose.

The field of substances from which the rubber ehem-
igt chooses those for any desired compound is ex-
tensive. In one of the large rubber factories, five
hundred raw materials, known as pigments are used.
Pigments are dried powders, such as zine oxide, lith-
arge, whiting, barytes, clay in various types, car-
bon black from natural gas, and so on through the long
list. Even crude rubber has ceased to be -of one or
two grades. It has become fifty different types, with
different sonrces, methods of preparation, degrees of
hardness, physical properties, and workability. The
factories use between fifty and one hundred grades
known as reclaimed rubber, which is the result of proc-

THE RUBBER MAN'S COOK-BOOK 47

easing previously vulcanized rubber products that
have ceased to perform their usefulneas — >scrap tireSp
old shoes, and the like.

The rubber chemist, therefore, has come to know in-
timately many thousands of materials. Like a good
cook, be must understand by esperi^ce what each
one will do in hia mixtures; and, like a highly scien-
tific investigator, he must know accurately if the re-
sults will be worthy of production and sale. In the
refinement of his business, he has become, therefore, a
sort of highly sublimated chef ; and his formula books
are the cook-books of rubber.

Let us follow the work of the rubber chemist. He
operates quite differently from the cook in the home;
for, if she has something new to make, she works it
out in the form of a real mixture on the kitchen table,
putting in a pinch of this and a little of that, using her
experience as a guide. In the rubber laboratories,
systems have been developed so that the chemist does
not himself weigh out his mixings; instead, he writes
his formula or recipe in his office. Here are his books
of reference, his samples of raw materials. If we fol-
low the formula written by this chemist from his office
through the various changes of its manufacture and
test, we shall go to a laboratory, in which are little
machines the same in principle as those in the great
factory. Here we obtain the fundamental informa-
tion that is expressed on larger scales in tires, shoes,
and other articles.

Our chemist may show us how he would make an
inner tube for an automobile tire. Inner tubes must
hold air, and be soft and flexible. They must stretch

THE REIGN OF RUBBER

with relative ease without tearing. A typical formula
would probably be: rubber of the highest grade, one
hundred parts by weight; sulphur powder, five parts
by weight ; zinc oxide, three parts by weight ; and an
accelerator such as hexamethylenetetramine or, as the
doctor knows it, urotropin, one half of one part by
weight. Written on a card, this formula is sent into
the laboratory compounding room. In this room
works the reliable old employee, who accurately weighs
these ingredients and places them in a tin box that is
carried out into a room where operate a number of
little mills, calenders, and vulcanizers.

Were our formula to be mixed on the full factory
scale, it would have appeared, before that process, very
much as it does in the photograph.

For purpose of test, it is customary in the laboratory
to vulcanize such a compound.in the form of a sheet.
In the photograph of the hydraulic press you will no-
tice two flat plates or platens with a little table at-
tached to the lower onej this is moved up and down by
hydraulic pressure. Upon the table lies a mold, which
is, in point of fact, a simple metal frame, made to re-
tain within a definite length, width, and thickness the
rubber to be vulcanized. The workman removes the
rubber from the mixing mill for testing purposes in
the form of a sheet of fixed thickness a little more than
that required in the mold. After he places the cover
upon it and slides it in between the two press plates,
he turns on the hydraulic pressure; then the mold is
squeezed, and the soft rubber compound fills the
cavity of the mold. Rubber, being a soft plastic
and flowing slowly under pressure, is not melted as

THE RUBBER MAN'S COOK-BOOK 49

iron is melted when cast into various shapes in the
fonndry. If we were to try to melt it, a useless prod-
net would result. In the mold there is always a little
extra volume of rubber, which flows out into grooves
and which we call the overflow, rind, or flash. This
overflow insures uniformity of pressure and vulcan-
ization in a solid, unblemished piece.

To furnish heat, steam is passed through the hollow
platens or the plates of the press. The particular
composition that we are discussing would probably
vnleanizo in forty-five minutes, with press plates at
a temperature of 290° Fahrenheit. To be sure, an
iimer tube would not be cured between plates in this
way; the formation of a tube we shall discuss in
another part of the book. In performing a test to de-
termine the properties of this composition after vul-
canization, the chemist would not simply pull it by
hand, as the old-time superintendent did. He might, it
is true, observe differences in the amount of force
neeeBBary to pull out such a piece a definite distance ;
kt such a test would not give data accurate enough
to distinguish between compositions of various kinds,
with materials in different proportions. Therefore
the rubber chemist, after removing the vulcanized
rind, takes his cured piece into the testing laboratory.
Here are machines and apparatus designed partic-
ularly to test rubber. Since rubber stretches to a
greater degree than any other known substance, we
must allow for length of pull in our test machin-
ery. Steel stretches but fractions of inches before it
breaks; rubber, six, eight, to ten times its original
length. It thins down as it elongates. Specially made

Lload, th
1^

THE SEIGN OF RUBBEE

jaws automatically contract against the piece of rub-
ber to be tested and prevent it from slipping out.

Let OS watch the test piece in the laboratory. On
the machine there is a dial to indicate the number of
potmds required to pull the piece a definite distance.
The operator marks lines two inches apart upon the
piece. When the rubber breaks, the distance of sep-
aration of these two marks gives him a definite fij^e
that he calls elongation, or stretch.

Of late years, the chemist has teen accustomed to
draw a picture of the course of this testing. As you
stand in front of the machine, you will notice at once
that the rubber piece stretches considerably with but
little increase in the number of pounds indicated on
the dial or the chart ; but that after it has stretched a
considerable distance, it resists more and more fur-
ther distortion. The little picture being drawn will
show us the force required to do the stretching.
Known to the chemist aa the "stress-strain," or
"force-stretch" curve, it portrays the relation inch
by inch between the elongation of the rubber and the
force producing it. Thus rubber writes its own auto-
biography, from the reading of which our rubber chem-
ist is able to determine a good deal of its value; he is
able to determine particularly the differences in the
values of substances to be used in the mixings.

In the formula an "accelerator" is used. Let us
concentrate our attention upon this substance for a
moment. Charles Goodyear might not have succeeded
in taming rubber had he not used in his mixture a
mineral powder known as white lead. Without white
lead, the mixture would have taken so much longer a

1 i

THE RUBBER MAN'S COOK-BOOK

time to vulcanize that he might not have observed,
least so qniekly as he did, the change in the propertii
of the mbber. Because white lead when used in
rubber mixture shortens the time of vulcanization, we
call it an accelerator. The combination of raw rubber

51 ^H

•ved, at ^^^
)perties 1

and sulphur by themselves would require several
houre under heat before enough sulphur would be com-
bined to give snappiness and the other properties of
vulcanized rubber. When white lead is used with the
rubber and sulphur, however, this time is reduced

52 THE KEKJN OF EUBBEE

to a short period. It happens in this particular case
that white lead itself changes in the presence of snl-
phur from a white to a black substance because, as the
chemist will tell us, of the formation of lead sulphide,
which is black.

These accelerators seem to serve as stimulants to
the combination of sulphur and rubber, just as when
yon place your foot on the accelerator of your automo-
bile, you permit more gas to flow into the cylinders,
and your automobile increases its speed. In a like
manner, when accelerators are used in the rubber mix-
ture, a more rapid flow or combination of sulphur with
the rubber takes place. In the chemical world they are
called "catalysts," and they are widely used in chem-
ical processes. The making of sulphuric acid re-
quires the use of catalysts in order that the combina-
tion of sulphur dioxide and oxygen may take place not
only within reasonable lengths of time, but with suf-
ficient completeness to make the process one of com-
mercial value. In the rubber process, the catalysts
themselves change somewhat; yet the definition
is broad enough to include any substance which facil-
itates the course of vulcanization. The first cat-
alyst, or accelerator, was the white lead used by Good-
year. For many years only such mineral substances
were used. Litharge or lead oxide aided in maMng
many of the best tires produced in this country. Lime,
magnesium oxide, and others have been and still are
common in rubber manufacturing practice.

Within the last few years publications have been
Betting forth the details of this ultra-secret phase of
rubber compounding. The better-trained chemists

THE REIGN OF EUBBER

to find him making every effort to determine the prop-
erties of other organic substances that might vulcan-
ize rubber with equal speed, furnish equal strengthen-
ing properties, and be free from poisonous character-
istics. This was too secret a matter to pennit of pub-
lication. As a result, these men have up to now never
received public credit for this tremendously potent
advance step In rubber manufacture. In 1912, how-
ever, some Germans patented in this country a con-
siderable niunber of organic substances for this pur-
pose. Once these disclosures were made, chemists in
the rubber business went ahead with great strides,
until to-day there are a large number of organic ac-
celerators in current use.

It is safe to say that there is scarcely a rubber mix-
ture that does not contain as an essential ingredient
some such substance. Of the many processes and sub-
stances that have increased the efficiency of au-
tomobile tires, no one of them deserves greater credit
than the organic accelerator; it has so greatly im-
proved the quality of rubber mixtures that tires run
much longer by virtue of it. The autobiographies,
called curves, strikingly show the gains attained by
these substances. Without an accelerator, a time of
two hours is needed to vulcanize a rubber-sulphur
mixture ; the strength attained is but 1150 pounds per
square inch; the piece stretches 6^4 times. Add one
half of 1 per cent, of accelerator and a little zinc oxide
to hustle the accelerator, and the mixture vulcanizes
in one hour, the finished product showing a strength
of 2760 pounds and a stretch of 6% times.

If these tests of mixtures were the only ones used

THE RUBBER MAN'S COOK-BOOK 53

have come to use synthetic organic chemicals as accel-
erators, for they have found them remarkable
powers of action and in giving a quality to rubber mix-
tures that had not been dreamed of before. The
organic compounds are, in the majority of cases, pro-
ducts derived from chemical processes upon coal-tar.
They are related to the organic dyes, many of which
are good accelerators. Some of them are drugs, the
one used in this formula being of that type. Only a
small amount of these organic accelerators is neces-
sary. Of the old inorganic, or mineral, ones, such as
white lead, formulas required from 5 to 15 per cent, by
weight; these new substances employed ao largely in
later years, however, require less than 1 per cent, to
give even more active acceleration. They seem also
to increase the strength of the rubber and its resist-
ance to abrasion, to heat, and to oxidation and aging.
The discovery and first use of the otgaoic accelerator
was nearly as great a^ step forward as that of vulcan-
ization.

To make history reliable, one must mention at this
point the name of a most able man of the younger
generation, Mr. Arthur H. Marks, and his assistant,
Mr. George Oenslager. To them goes the credit for
the first introduction of a typical organic accelerator
in commercial rubber manufacturing practice. In 1906
the records of the Diamond Rubber Co., of Akron,
Ohio, later combined with the B. F. Goodrich Co., show
that they first employed aniline oil as an accelerator
of vulcanization. Because of its poisonous nature,
this substance had one disadvantage. It is quite nat-
ural, once Mr. Mark's mind turned in this direction,

56 THE BEIGN OF RUBBER

parts, plantation raw rubber one hundred parts, and
the accelerator hexamethylenetetramine one part.
The photograph shows the relative volumes of Ihese
substances after they had been weighed out. The new
compound cures in about the same length of time,
forty-five minutes, at a temperature of 290° Fahren-
heit, as did the other. The autobiography of the test
specimen though, is quite different. It is harder ;
more force is needed to stretch it. When it extends
to six times its length, a load of more than 3400 pounds
to the square inch is required to break it. It resists
abrasion better.

The chemist and physicist, who must really be the
same individual in the rubber testing laboratory, meas-
ures another property, the energy stored in rubber
when it is stretched. Engineers compute work in
terms of resistance to lifting weights- against the force
of gravity. If one pound of a material of any kind
be lifted one foot the engineer and physicist call the
work done the foot-pound. When our rubber test
piece was stretched in the machine, it was necessary
for the machine to perform work upon it. From the
autobiography or stress-strain curve, a definite mean-
ing regarding an interesting property of rubber is ob-
tained. This stretched piece has a strong desire to
return to its original length. That is why it is rubber.
If you stretch wood and steel, they also have a desire
to return; but the distance you can stretch them with-
out destroying that desire is very small. Rubber,
however, is something like the small boy who climbs
the old windmill. He goes up quickly at first; and
then much slower as he gets near the top. His feet

THE RUBBER MAN'S COOK-BOOK

lag toward the end ; his enthasiasm seems to die. Rub-
ber acts in much that way. Yielding easily to a light
load in the beginning, more and more force must be
exerted to perform the work of stretching it to its
maximum distance.

Engineers say that whenever any substance is lifted
above the ground against the force of gravity, there
is stored in it a certain amount of energy some of
which can be regained in the form of useful work by
machinery properly designed. Although rubber is not
stretched against the resistance of gravity, the work
performed is done against the desire on the part of
(he rubber to return to its original length. From our
chart we are able to measure the amount of this work
or energy in the engineer's unit of foot-pounds and to
compare the amount of stored energy in the rubber
with the amount that may be stored in other sub-
stances.

Each substance has a definite limit to its ability to
return to normal condition. Steel, for instance,
may be stretched but a short distance and still return
nearly to its original length. If steel be stretched be-
yond that short distance, which is measured in small
fractions of inches, it cannot return. This limit of
stretch beyond which substances cannot return has
been called, in our books of physics, the elastic limit.
Thus, if a bar of ordinary steel one inch square and of
a length sufficient to be placed easily in a testing
machine have applied upon it a force of 40,000 pounds,
it can be pulled out only about one-hundredth of an
inch; from this extension it will return to its original
length. To break the piece, however, would require

58 THE REIGN OF EUBBER

68,000 pounds; the same force would stretch it about •
four one-hundredths of an inch. Thus, any load up-
on this test piece of steel between 40,000 and 68,000
pounds is too great for it to bear and stil! return to
its original dimensions. For almost all metals, the
elastic limit is decidedly less than the number of
pounds required to break the piece.

Rubber is singular and different from other sub-
stances in the fact that its elastic limit and breaking
point coincide. One can stretch a piece of rubber to any
distance under its breaking point ; and when the load
i6 removed, it promptly returns to approximately its
original length. This slight increase in the elonga-
tion after stretch and release, known as the "perma-
nent recovery" or "permanent set" or "permanent
elongation," is a characteristic of all rubber articles.
On long standing, this permanent recovery gradually
becomes less and less ; and it varies widely in rubber
mixtures of different composition.

The ability of rubber to store energy is great ; that
is, we may pull rubber to nearly its breaking point.
If it were possible to harness this energy so that use-
ful work could be performed, we should find a rela-
tively large amount of it stored in rubber. If, in a
machine, one pound of tempered spring steel be
stretched just to the elastic limit, an action which
would require a bar an inch square in section and
weighing one pound to be loaded with 82,000 pounds,
one can store in it 95.3 foot-pounds of energy. Hick-
ory wood when pulled along the grain is elastic enough
to permit the storing of 122.5 foot-pounds at its elas-
tic limit. In this way, our pure gum rubber compound,

THE RUBBER MAN'S COOK-BOOK 59^

without the accelerator that we have already deaeribed,
would permit us to store in it a matter of 3186 foot-
pounds. However, with the accelerator, we can store
7633 foot-pounds; the zinc oxide composition, on the
other hand, would store 7988 foot-pounds.

But, you protest to the chemist compounder, most
rubber articles are not white I Tire treads are black;
at least, they are that color when the gray bloom is
rubbed off. Heels and shoes are usually black. If
zinc oxide is so valuable a material, why use any other
dry powder? Then all articles would be white except
those articles where other colors were desired. But
you would not be quite happy were the rubbers you
wear always white, because they would discolor too
easily ; they are deliberately made black. However, a
discovery in this field was made which brought into
use a material that was formerly well known, but that
entered rubber in a new way.

Carbon-black is a soot made by incomplete combus-
tion of natural gas; it is composed of very fine, light
particles. Let us now make a new formula in which
this black dust is used, to see how it compares in physi-
cal properties with the others. This will lead us to
the reason for its wide use in the rubber industry. A
formula composed of rubber one hundred parts by
weight, zinc oxide three parts, gas-black thirty-five
parts, sulphur five parts, and the same accelerator
one part, is a good one. If this composition be vul-
canized, we find relatively little change in the time
of vulcanization. When its autobiography is in-
scribed on the chart, we find that with a cure of
seventy-five minutes at 290° Fahrenheit, a load of

60 THE REIGN OF RUBBEE

twelve hundred pounds has stretched the piece only a
matter of 2.6 times its original length. But a force
of nearly four thousand pounds to the square inch is
needed to break it ; and under this load, it has stretched
to 5.5 times its length. The mixture is therefore stiffer
and stronger. The piece stores 14,887 foot-pounds.
In weight it is very much lighter than the zinc oxide
mixture; as we find, on measurement, that the specific
gravity of this particular mixture is only 1.09, a figure
which means that the weight of a cubic foot is sixty-
eight pounds; the zinc oxide mixture with a specific
gravity of 1,56 shows a weight of a cubic foot to be
ninety-seven pounds. In the formulas approximately
the same volume of zinc oxide and carbon-black was
specified. Zinc oxide is heavy and dense, and so a
cubic foot of the- compound weighs more than that
which contains black. ;

The gas-black formula will wear ^way less readily
than the others. Since this.subst^nce produces radical
improvement in the physical properties required for
wearing qualities, it is valuable in the treads of auto-
mobile tires. The gas-black tread has become stand-
ard. In the interior of the tire a carbon-black com-
position would be worthless ; it generates heat as it is
stretched back and forth. In masses of rubber it be-
comes a heat insulator, and compositions in which it is
used become very hot in service. Without organic
accelerators, though, gas-black compositions are too
"dead" for practical use; with the accelerator and
with zinc oxide, they are valuable and economical.
Zinc oxide alone gives a strong but more resilient com-
position.

H^ THE RUBBER MAN'S COOK-BOOK 61

»' Each of these two substances then has its own partic-
ular properties, and the chemist uses them to improve
lie compositions. We could not do without either
of them. They are the royal family of the rubber
pigments. Each rubber chemist chooses which one of
them is to be the king. One thing is perfectly sure:
the addition of dry mineral powders is necessary to
obtain valuable properties in rubber mixtures for dif-
ferent uses.

It would not be wise to say that all dry pigments
used in rubber mixtures should be only zinc oxide and
gas-black. If that were the case, there would be many
common articles that would render less service than
they now do, as each pigment has its own particular
valae and each one is used in rubber for the service
that it renders.

We may mention other materials: such as mineral
rubber, a material derived from pitch and soft, flexible,
mineral hydrocarbons; rubber "substitutes," resins
and many others.

I shall not at this point discuss reclaimed rubber, a.
valuable substance made in the recovery of old vul-
canized tires, shoes, and so on. Since the saving of
waste is a most vital part of industry and human man-
agement, it would be folly for a great industry to per-
mit the total loss of these waste products. Old iron
goes back into the melting pot and is reworked into
various articles. So the rubber industry has suc-
ceeded in reclaiming its vulcanized products after they
have performed all the service possible-
Colored goods introduce another phase of rubber
compounding. It seems that the human race demands

THE REIGN OF RUBBER

foot-balls, there being no need to blow them. . , , They
might strike it every time it rebounded, which it woald do
several times one after another, in so much that it looked as
if it had been alive.

He alludes to the natives of Tierra Firme, who "on
their festivals, painted or daub'd themselves with a
sort of clammy gum, sticking on it feathers of several
colors. ' '

F. Juan de Torquemada, in the third volume of his
*'De La Monarquia Indiana," of which the first edi-
tion appeared in 1615, describes the Mexican Indians
as making shoes, head-gear, clothing, and other water-
tight articles of the gum of a tree.

The actual introduction of any useful articles into
Europe seems to have followed the colonization of
Brazil in the early part of the sixteenth century by
the Portuguese.

In 1736, in company with Bouguer and Godin, La
Condamine, a French savant, was sent by the king
of France to South America for the purpose of meas-
uring a degree of the meridian. On their return jour-
ney to Europe, these men brought the first specimen
of caoutchouc from Peru, by way of the Amazon River.
La Condamine reported having also found this "most
singular resin" to the north of Quito in Ecuador, exud-
ing from a tree named hive or hyeve. It was called
pao de xyringa by the Portuguese colonists. The re-
sult of his observations was published in the "Trans-
actions de 1' Academie des Sciences," wherein he de-
scribed the various methods of collecting the juice and

?^^^ '

Coanesy ot The B. F. Goodrich Ci).

PPI

1t!|K;_j;_:

— ^JC -^ (^Sl

RAW RUBBER

of treating it for the production of many useful ar-
ticles.

Herissant and Macquer published in 1761, in the
"Memoires de 1 'Academie, " the results of the first
chemical investigations of India rubber solutions.
Five years later, Macquer reported fully on the means
of dissolving the "resin caoutchouc" in ether, and
on repeatedly coating forms, so that they retained a
covering of the gum after the evaporation of the ether.
In 1759 the government of Para presented to the
king of Portugal a suit of rubber clothes ; four years
previously he had sent several pairs of his boots to
Brazil to be waterproofed. One of the Portuguese
drank some of the milk, but his stomach did not care
to be waterproofed and he passed on to his fathers.
An Italian engineer suggested in 1791 the suitability
of petroleum as a solvent; but he was ahead of his
time, for that substance did not come into general use
until as late as 1860, with the exploitation of the
American oil-fields.

But on May 2, 1791, Samuel Peal was granted in
England the first known caoutchouc patent. It was
for a method of rendering "perfectly waterproof all
kinds of leather, cotton, linen, and woolen cloths, etc."
His coating consisted of India rubber dissolved "by
distillation or by infusion in a small quantity of tur-
pentine over a brisk fire, or by infusion in other spirits
and in most kinds of oil ; or of Indian rubber used in
its native fluid state."

Samples of this crude rubber coming into England
found their way into various laboratories, where

I
I

68 THE BEIGN OF RUBBER

the course of a day. After he has properly tapped
the trees in his territory, he goes back over it and
pours the milk from the Utile cups into his tin bucket.

His milk collected, he comes back to his hut which,
during the dry season, is usually a temporary one on
the ground. While he prepares Lis meal, he lights a
fire made from wood and specially collected palm
nuts. Over this fire he places a conical, baked clay
flue to concentrate the smoke. Obtaining a dense,
hot smoke, he begins the work of preparing the raw
rubber for market. He warms a long stick or a paddle
over the fire ; then he pours some milk upon it. This
he rotates in the smoke until the milk has dried on the
stick. Again he pours the milk, and again he dries
it over the fire. If he is not asphyxiated at the out-
set of the performance, he keeps at it, building up
layer after layer of evaporated rubber until a mass
is obtained nine or ten inches in diameter and about
eighteen inches to two feet in length. This forms
the biscuit of wild rubber called "fine para" seen in
our markets. Weighing about sixty to eighty
pounds, it constitutes a day's work for the tapper.
It smells like fine old Virginia ham.

At the end of the day, which for him is about three
in the afternoon, he may be found in his hammock,
with sore eyes, parched and smoked face, bitten by
insects, and covered with soot. It is no wonder that
we find a high death-rate in the Brazilian swamps
and that there has been from the beginning a steady
deterioration in both numbers and quality of labor.
At the end of the dry season, for the tapper cannot
work at all during the wet or rainy season, he collects

RAW RUBBER

and binds together the product of a year's work, and
floats it down the river to the nearest chief, who ac-
cepts it in payment for money previously advanced.

The Brazilian rubber industry was important for -a
considerable number of years, but the history of it is
dark and morbid. The prevailing practice has been
to make peons, mere slaves, out of these poor Indians.
Couple this with the heavy government taxes and fees,
the high freight-rates, the dishonest gradings of rub-
ber, and you will not wonder that the collection of
raw rubber in Brazil has sagged during recent years.
Attempts have been made to import farmers ; but be-
cause of unhealthy conditions, the lack of proper food,
the absence of business ability on the part of the "Bra-
zilians, their indifference to progress, and the damp
air and lands, the attempts came to naught.

The slowness of evaporating the several coats of
latex to produce the thin layers of rubber built up step
by step into the biscuit, together possibly with the
chemical constituents of the smoke, served to yield a
tough, high-quality raw rubber. Although the native
lost his health and life, he succeeded in producing the
finest grade of crude rubber that came into the mar-
ket. This was known as "fine bard para." It is
singular how a name is preserved, for Para was the
original port of shipment. In later years the port
became Manaos, although the name "para" rubber was
still ^ven to the best grade from Brazil. Not only
that, but all high-grade rubber is colloquially known as
"para" rubber. If the workman is not skilled, the
layers on his biscuit are apt to be thick and soft ; the
grade "medium" is the result. When the tapper

70 THE EEIGN OF RUBBER

collects the little strips of rubber that have gath-
ered on the trees, and on the leaves on the ground,
he rolls them, fuU of dirt and bark, into balls known
as "coarse" or "semamby." In the bottom of the
cups are always little cakes of rubber; these come
in mass form into the market under the name
"cameta." These are but a few of the many grades,
each distinct from the other, produced from this exuda-
tion from the wild trees in the Amazon Valley. There-
fore the rubber manufacturers' problem during the
days when wild rubber was at its ascendancy, was one
of making the correct selection for many different pro-
ducts. Because all the grades were wet, it was neces-
sary, and stiU is, to wash these wild crude rubbers
free from sand and other particles of foreign matter
and to dry them before they are ready for use in the
factories. In washing and drying there is a loss of
weight called "shrinkage," from both dirt and mois-
ture. In the highest grade the shrinkage is about 17
per cent. ; in the softer, weaker grade, such as the
cameta, it runs as high as 48 per cent.

Rubber-trees in different districts seem to be a little
unlike even in the same species. This, with slightly
differing methods of production, results in many
grades. Names of different rivers are used in desig-
nating grades — Acre, Tapajos, Madeira, and so on.
Since the best trees and the best rubbers from
them come from the upper reaches of the Amazon
River, it has been natural for the trade to call these
products "up-river." So "up-river fine parii" is the
highest grade known, except "beni," which is the
best of the up-river grades.

RAW RUBBER

' Men somehow are never satisfied. No sooner waa
wild rubber known than suggestions came to plant the
trees. Dr. James Howison, an English surgeon at
Pullopinang, in 1789 discovered a vine giving a milk
that possessed the properties of the South American
eaoatchouc. He wrote about it in 1800 : ' ' Should it
ever be deemed an object to attempt plantations of the
elastic-gum vine iu Bengal, I would recommend the
foot of the Chittagong, Eajmahal, and Bauglipore
Hills, as situations where there is every probability
of succeeding, being very similar in soil and climate
to the places of its growth on Prince of Wales' Island."
Howison thus originated the plantation idea.

Later Thomas Hancock, in 1834, expressed in the
"Gardener's Chronical" the probability of cultivating
the best kind of caoutchouc-bearing plant of the East
and West Indies. The supply at that time — two to
three tons weekly — did not seem great enough I It
came to England in poor condition, wet, sticky, and
dirty.

Fortunately, in the early sixties one roan saw a vis-
ion of the future and carried it out. Henry A. Wick-
ham of London had spent several years in the Brazil-
ian forests. A man of keen mind, intrepid force of
character, and vision, he studied the rubber-trees and
went 80 far as to plant trees on the Tapajos Plateau in
Brazil. He posted himself thoroughly on the botany,
the method of growth, soils, water supplies, and every
other possible question connected with the Hevea tree.
He proposed to London that seeds from the Eevea
brasiliensis tree be gathered and planted for the pro-
duction of cultivated rubber-trees. Others had tried

72 THE EEIGN OF RUBBER

it but failed ; they had chosen the wrong species. Mark-
ham had sent Collins to investigate. Cross had
brought back Castilloa seedlings ; but the plants never
thrived, and the rubber gained was of low grade. Sir
Joseph Hooker, then director of Kew Botanic Gardens,
believed in Wiekham'a plan and interested Sir Clem-
ents Markham of the India OEBce. Luckily, Wiek-
ham was given the responsibility of making the exper-
iment, and by rare good fortune he was left unham-
pered by instructions. We must commend the English
for one thing; when once their minds are made up,
they see a thing through.

Setting out again then for Brazil, Wickham went
immediately to the territory on the Tapajos Plateau,
well up the Amazon Biver, where he had been con-
sidering a plantation enter-prise. He writes a roman-
tic story of his experiences. Singularly, discouraging
circumstances were turned into success by an accident.
While he was in the district, word came to him
of the arrival of the steamship Amazonas, Captain
Murray at the helm, which was the first of the new
"Inman line of Steamships — Liverpool to the Alto-
Amazon direct." A few days later the information
arrived that this fine steamship, through a mix-up, had
been abandoned by the supercargoes and left on the
captain's hands, with nothing to take back for the
return voyage to Liverpool.

Wickham was nothing if not an opportunist. He
had neither cash nor credit. The seed was just ripen-
ing on the trees. But he boldly wrote to Captain
Murray, chartered the ship on behalf of the Govern-
ment of India, and made an appointment to meet him

RAW RUBBER

at the junction of the Tapajos and Amazon rivers.
Here he was in the jungle, with an impatient captain
waiting at port on an empty steamship. Jumping into
an Indian canoe, he paddled np the Tapajos, a danger-
ous trip, particularly in that season, and struck back
into the woods where he knew the full-grown Hevea
trees to be. Out of seventeen varieties, he chose seeds
from the black or best grade of the tree. Accompanied
by Indians he daily went through the forests and
packed pannier baskets with loads of seed. It was a
delicate operation, for the seed is rich in a heavy oU
that quickly becomes rancid, a condition that destroys
the power of germination. With remarkable astute-
ness he did what no other ^ad done — packed the seed
to avoid decay. Once on board the steamer he went to
the city of Para, from which port clearance papers were
necessary before he could go to sea with his cargo.

Wickham says in his narrative: "It was perfectly
certain in my mind that if the authorities gnessed the
purpose of what I had on board, we should be detained
under the plea of instructions from the Central Gov-
ernment at Rio, if not interdicted altogether." Any
such delay would have rendered his seeds useless. He
had, however, a friend in the person of Consul Green,
who entered into the spirit of the occasion and made
a special call with him upon the chief of that district.
They represented that they had "exceedingly delicate
botanical specimens specially designed for delivery to
Her Britannic Majesty's own Royal Gardens at Kew."
This seems to have been impressive; and, after the
usual complimentary interview in the best Portuguese
manner, they were permitted to clear port.

THE REIGN' OF ETTBBEE

On the voyage Wickham took exceeding care of his
precions geeds. Daring June, 1876, he arrived in
England. A special train was sent down to meet him
at Liverpool, and the seven thousand young seeds
were promptly planted in the Botanical Gardens at
Kew. A fortnight later they had sprouted. Then an
equally great problem confronted the experimenters,
for no plans had been made to send the shoots to any
of the English colonies. They were originally intended
for southern Borneo ; but because of the depres-
sion in business at the time, the government forestry
appropriation had been decreased. Governments cut
down the amount for research in those days as now.
As a result of this decrease, the seeds were sent to
the Eastern Tropic Botanical Gardens in Ceylon.
Thus the plantation industry was started. Wickham
was knighted in recognition of these services.

In 1877 twenty-two trees started in Ceylon were sent
to Singapore in the Straits Settlements south of the
Malay Peninsula. Some were planted in Singapore
gardens and the rest taken to Perak. A few of these
original trees are still standing. One of them is said
to be the biggest plantation tree in girth yet recorded.

They bore fruit in Singapore first in 1881, and
seed was sent to Borneo and Malaya. Because they
had been making good profits from the growing of tea,
the planters in Ceylon did not take hold of rubber
planting with the same aggressiveness as did the plant-
ers of Malaya. But in Malaya, backed by financial in-
terests in Europe and tired of the struggle to make a
living out of coffee, rubber appealed to them, and they
planted trees wherever possible. The first trees of

BAW BUBBEB 75

the Ceylon plantation bloomed in 1881 at Heneratgoda,
sixteen miles from Colombo. That year the first ex-
periment in tapping began. Problems of how to tap
and when to^ tap, of how many trees to plant to the
acre, of the diseases of trees and methods of treatment,
and of the proper handling of latex, have filled volumes
of literature. It is, in a marked degree, due to the
enterprise of the English and Dutch scientists and
business men that the plantation industry has suc-
ceeded and has become so tremendously important in
the world *s markets.

From the wilds of Brazil to the cleanliness and uni-
formity of the plantations of the East necessitates a
change of picture. Here the trees are laid out in or-
chards as even, regular, and well cultivated as apple
orchards. There are little Chinese and native rubber
farms and big ones, owned by corporations with head-
quarters in London, Amsterdam, and America. On the
plantations the health of the workers is taken care of.
Because there is not labor enough in these districts, it
has become necessary to bring in coolies from China
and India. In order to make the conditions as com-
fortable for them as their natural state of living re-
quires, the health, the food, and the life of these people
are watched, and the result has been economy in op-
eration and increase in production.

To start a plantation, the jungle must be cleared in
a location where drainage and soil are right. It is a
long, expensive task to prepare land for the reception
of the rubber-tree sprouts, which are set out in rows,
usually about one hundred to two hundred to an acre.
Then begins the important problem of exterminating

THE EEIGN OP RUBBER

weeds, which in these moist, tropical regions grow at
a discouraging rate.

The tapping of a mbber-tree is an art that requires
a delicate tonch and a sure hand. By tapping is
meant the cutting of the tree so that the latex wUi
flow freely in a clean, uncontaminated condition, into
a properly placed cup. Scientists spend their time
in improving the yields by procesecs of tapping at
proper intervals, by care of the trees, by selecting
seeds for future plantations from those that give the
greatest yield of rubber. Eubber-trees are being
scientifically bred and trained, like cows, to ^ve
greater quantities of milk, A diagonal cut extending
one third or one quarter of the way around the tree is
one of the best of many metHc^s. This is made with
a razor-sharp knife of special construction, whose blade
is so thin that twenty tappings may be made side by
side in one inch of bark. If the cut be not sufficiently
deep, the full quantity of latex is not obtained; if the
cut be too deep, the tree is injured. Tapping is there-
fore so important that only a skilled laborer is per-
mitted to do it. Because the latex is found in milk
ducts, it is necessary to tap a tree daily. These glands
seem to rebuild themselves after a few days' rest. By
noon, when he has tapped 450 trees, the tapper's work
is finished; at eight or eight-thirty in the morning, the
work of collecting the latex from the little cups begins.
Usually on the large plantations metal milk cans are
used ; and when the collector has filled his cans, he takes
them to a collecting shed where his latex is weighed.

The plantations are milk factories. Here, cleanli-
ness is as necessary as in a dairy. Rubber milk is

RAW RUBBER

even something like cow's milk. Both contain finely j
divided particles suspended in water; but in one case
it is 3 to 5 per cent, of i'at and in the other 25 to 35 •
per cent, of rubber. The farmer centrifuges milk I
and gets cream, but milk separators do not work on
Hevea latex. Since the rubber will not rise as a
cream, the planters add acetic acid to it to congeal or
coagulate it.

On large plantations, the first operation is to strain
the latex carefully in order to free it from dirt and
from the curds or flocks that have been formed during
transportation. Into appointed vats of correct size
the latex is then poured, and with it is intimately
mixed a dilute solution of acetic acid. This causes
immediate coagnlation into a mass of soft, white dough.
The acid must be added within twenty-four hours, or
spontaneous coagulation will set in, caused probably
by the rapid action of bacteria that seem to sour the
rubber milk just as bacteria sour cow's milk. After
this soft, white dough baa formed, it is put into a ma-
chine which tears it up into small pieces and presses out
the excess of water and chemicals. It then goes
through a washing machine, where it is washed ■with
clean, filtered water; during this process it gradually
hardens by the simple matting together of the rubber
particles that bad previously existed in the latex. On
the larger plantations, it is usually coagulated in bulk,
either in a big tank or in glazed earthenware jars of
200 to 250 quarts capacity.

In order to produce the light yellow crepe rubber,
there is mixed with the acetic acid a small quan-
tity of what the chemist knows as sodium bisul-

7S THE REIGN OF RUBBER

phite. The rubber comes from the rolls of the washer
in a rough irregular sheet. This wet rubber is hung
in dry rooms, like clothes on a line. Before it is dry,
the rubber is white from the presence of water. From
the dry room, the sodium bisulphite having bleached
it, it emerges pale yellow in color. We call it "pale
crepe."

The Amazon fine para smells smoky, like ham. So
older rubber men thought smoked rubber to be the best.
The planters met the demand for the smoked prod-
uct with the grade known as "smoked sheets." To
make this, the method of coagulation is essentially
the same, but without the sodium bisulphite. The eo-
agulum is then rolled between washing rolls. When
clean, it is passed between rollers that have been cut
in such a way as to produce a pattern known usually
as "ribs" upon the soft, wet mass. Less time is re-
quired in washing and handling smoked sheets than
in producing crepe, but there is danger that all the
impurities and serum are not removed.

The Rubber Growers* Association of Great Britain,
and similar associations among the Dutch, have worked
out methods to produce "even size, even weight, even
thickness" of sheets. After the rolled sheets with the
pattern or ribs come from the mills, they are hnng up
to dry. Then they are smoked in a smoke-honse,
much as we smoke hams. Great care is taken that
the smoking be uniform, that it be not too hot, and
that the color be regular ; for by irregularity of han-
dling the smoked sheets comes a large variety of de-
fects that grade down quality. There are ten or a
dozen different types of smoked sheets produced by

RAW RUBBER

different conditions of coagulating and smoking.
There are bubbly sheets, moldy sheets, tacky sheets,
dark colors, and light colors. To the farmer, milk is
milk and cream is cream; he disposes of it all in one
grade. The problem is not so simple for the rubber
planter. Besides pale crepe and smoked sheets, there
are clots in the strainers, bark scrap, and eup film,
which are often worked together and called "compo."

The natives, too, on their little farms grow rubber-
trees. They, however, follow the simple plan of pour-
ing latex into pans, permitting it to evaporate until
it has coagulated. Then they roll it up with a sort
of rolling pin to squeeze the extra water out, and
hang it on the fence to dry. This process yields a
softer product, one that is wet, somewhat oxidized,
and not of a high quality. The enterprising China-
men trade rice and clothing for the rubber produced
by these natives, and take it to central stations, where
it is washed and dried. We call it "amber sheets,"
which are rated according to color.

One might think the rubber planter to have finished
when he takes his sheet from the dry room. This is
far from the case; for then a number of different
forces begin to act upon it. Because sunlight causes
rapid oxidation, the rubber must be kept from it; be-
cause heat causes a chemical change that renders
rubber less useful, it must be kept as cool as possible.
Care must be taken in packing and storage. Bacteria
affect the rubber. Oil from machines produces soft
spots. If it is packed in the rain or if it is not properly
dried, mold develops on it; and some mold is delete-
rious. The proper kind of boxes in which to pack the

loking. ^^H

sheets. ■

^ i

THE BEIGN OP RUBBER

rubber haa been the subject of much study; for if the
box, which holds about two hundred pounds and is
approximately cubical in shape, be weak and break,
the rubber may be contaminated with chips. Chips
in inner tubes of automobile tires might affect one's
good humor.

A glance at the map will show you the areas from
which plantation rubber chiefly comes. The vicinity
of the Malay Straits seems to offer that peculiar
combination of soil, climate, and labor around which
the successful development of the plantations has
grown. From the little experimental trees set out in
Ceylon, there was not a great or rapid development
until the automobile brought a demand for rubber
tires. This demand induced further planting. Statis-
tics show that in 1900 there were four long tons of
plantation rubber recorded, with 26,750; tone of wild
rubber from Brazil and 27,136 tons from the rest of
the world, or a total of 53,890 tons. For the first
time in the history of rubber it had a statistical posi-
tion that marked it as permanent and large enough
a product to warrant the attention of the world. The
industry then rapidly grew, so that in 1907 one thou-
sand tons of plantation rubber are recorded, with
38,000 of wild rubber from Brazil and 30,000 tons from
the rest of the world. In the same year, there were a
total of 506,550 acres of ground under rubber cultiva-
tion. The automobile in those years became a potent
factor, and the demand for tires rapidly increased.
Consequently predictions of the optimists became
realized; in 1909, plantation rubber had jumped to
3600 tons and wild rubber to a total of about 66,000

RAW EUBBEE

tons. The area under cultivation had grown to
861,000 acres.

Then occurred the famous aud spectacular * ' rubber
boom" that has gone down into history like the many
speculative entanglements. Never has there been a
more memorable year in the history of rubber than
that of 1910. Men went as wild in England during this
period of over-speculation as they did at the time of
the South Sea Bubble or of the tulip mania In Holland.
Our statistics show that crude rubber prices varied
from a low point of about forty cents in the year 1878
to a high one of $3.12 a pound in New York in April,
1910. During those exciting days in London, investors
even paid as much as 4600 per cent, premium for
shares in rubber plautations. Speculators who knew
little of rubber besieged bank doors when the list of a
new company was opened. "Waitresses, hair-dressers,
elevator-boys speculated and made, at least on paper,
money enough to retire to the ranks of the "bloated
bondholders." Then came the break, and rubber
prices have steadily declined ever since.

The stimulus to planting, however, was permanent,
the total area under cultivation rapidly increasing,
until in 1915 it had reached 2,293,000 acres, and in
the next five years, 3,02Q,750 acres. The production
of plantation rubber likewise kept increasing, as did
the production of Brazilian and other wild rubber,
but less rapidly. As a result, in 1915 there were
107,860 tons of plantation rubber, 37,220 tons of
Brazilian, and the rest of the world yielded only
13,616 tons. In 1920 the plantations put into the
market 304,816 tons, Brazil had fallen to 30,790, and

THE REIGN OF RUBBER

the remainder of the world, to 8125 tons. Seventy-five
per cent, of all this rubber came to America, and abont
70 per cent, went into tires manufactured here and else-
where. The far-sighted planter had won.

During the boom of 1919 and the depression of 1920
we again notice rubber's elasticity. For while mil-
lions were made in the boom of 1910, millions were
lost in the depression of 1920. In this depression,
over-production played the star part. After the
World War the demand for automobile tires and rub-
ber products rapidly increased; the supply of crude
rubber increased in about the same ratio. But with
the depression, the planters were in a difficult situa-
tion. The larger number of estates were owned by
the English, who consequently felt the slump most
keenly. Singapore, instead of Para or Manaos, had
become the world's shipping center, with London the
world's rubber financial center. The end of Decem-
ber, 1921, showed a total acreage under cultivation in
British Malaya of 1,760,000 acres; In the Dutch East
Indies of 875,000 acres; in Ceylon of 410,000 acres;
and in the other countries of 276,000 acres, making a
total of 3,321,000 acres. The total amount in bearing
and still solvent amounted to approximately 2,200,000
acres. These estates gave an average yield of 316
pounds to the acre, so that the production in 1920 was
309,100 tons, The demand for use could not possibly
be more than 180,000 tons. With a visible supply of
well over 300,000 tons, there was little hope for a pro-
fitable market. Since a selling price of eightpence per
pound was under the cost of production, strenuous ef-

RAW RUBBER

forts were required to maintain the Bolvency of the
rubber plantation companies.

The real needs of the plantation industry may be
summed up thus: Prices must be suflSciently low to
maintain the economic balance of supply and demand ;
cheaper production must come from efficient and eco-
nomical management. These needs met, if world-
business conditions be sound and normal, the planta-
tion industry will keep alive, growing, and successful.
From the rapidity with which unattended estates in the
tropics become overrun by weeds, there is, though, a
serious condition confronting the plantation industry
and the world's use of rubber. The maintenance
of a rubber plantation in good bearing condition re-
quires labor to be expended in removing weeds and
treating tree disease, regardless of any tapping or
profitable output. When there is no money to be real-
ized, or so little that what is realized is less than the
cost of production, it is natural to let young orchards
lie unattended. The result is an outgrowth of weeds
which rapidly chokes the young trees. The care and
money that have been spent in clearing the jungle are
thus lost, and years will be required to bring many
thousands of these acres back into good condition.

It is still too early to prophesy the extent of the
labor problem in the Malay Straits. Every estate is
cutting down its labor. Coolies are returning to India
or China. Emigration has become greater than im-
migration. When production is required, it will take
a long time and an expensive process to recruit these
coolies again and train them for the work. On large

THE KEIGN OF KUBBER

estates and on small ones the cost of production, hor- 1 «
ever, must be brought down low enough to penmt I a
profits to be made at prevailing prices. 1 1

I have thus far spoken but little of the wild rnttber I ti
produced outside South America ; and but little need be 1 1
said, in view of its declining quantity. Rubber has
been produced in Africa. The qualities were as vari-
able as the climate and the peoples of that great coun-
try. The majority of processes for obtaining rubber
from the latex were crude in the extreme. Much of it
was obtained by spontaneous coagulation on standing,
some by heating of the latex, and some by the use of
juices from trees and vines. Foul smelling, it all
needed washing; and the rubber man soon learned
to recognize the grade of rubber by the odor.

Experiments have been tried in the Philippine
Islands, where it has been found that the Ceard tree
will grow rapidly and come into bearing under cultiva-
tion in from three to ten years. Crop conditions are
favorable in the southern part of the Philippines out-
side of the typhoon belt, but no forward strides have
been made. Development probably is retarded by the
laws prohibiting a corporation from engaging in cul-
tivation or control of more than twenty-five hundred
acres of land. The Far East has the start, therefore,
in plantation rubber production, and it is doubtful
if any other country will for many years catch up with
it.

There is one country, though, in which rubber has
had a spectacular rise and fall; namely, Mexico. Id
1852 Dr. J. M. Bigelow discovered a plant in the form
of a small shrub that contained rubber in the wood. It

EAW RUBBER 85

^«ras called guayvle by the Mexican peon. No ntili-
ssation of it, however, except by natives had been made
until 1888, when a company went to Mexico and ob-
tained a large quantity of the shrub, from which to ex-
tract the rubber. Later, the methods of extraction •
were developed to the point where the industry became
a large commercial enterprise with many millions of
dollars invested in it. Large supplies of the shrub
were used, many thousand tons of the product being
employed in the rubber industry. But the rise in vol-
ume of the plantation grades, the decrease in the cost
of those grades, and the political conditions in Mexico
have led to a gradual decrease of guayule in the mar-
kets.

Booms in the industry have led also to a study of
every possible plant from which rubber might be ob-
tained. In late years surveys have been made of
western North American shrubs; even the Carnegie
Institution and the University of California have pub-
lished documents giving the rubber content of some
species. The work was originally undertaken as a
war measure for emergency supplies. Energetic
Americans studied about 225 species of western North
American plants, which they grouped into two classes :
one in which rubber occurs in solid particles, as in the
Chrysothamnus ; the other in which it occurs in sap,
as in the milkweed and Indian hemp. They seem con-
vinced that if natural rubber is ever produced in the
United States in commercial quantities, it will come
from plants the maceration of which will result in the
isolation of small quantites of rubber from much ex-
traneous material. The cultivation will require large

America is supposed to be a wasteful nation. The
lumberman has from the beginning of our occupation
of this country followed pretty generally the practice
of skimming the cream. Out of the millions of cubic
feet of wood in the forests an appallingly small per-
centage of it is finally worked up into useful products.
Contrariwise, almost all of the old iron is collected
and remelted; the steel industry utilizes its waste prod-
ucts.

There is a difference between the old or scrap prod-
ucts and the by-products from industry. Many in-
dustries produce substances other than the chief ones,
which are sold to advantage. The dye industry is built
upon coal-tar, a by-product in the manufacture of coke.
Coke is necessary to steel manufacture, but steel has
no use for tar.

The rubber industry has few by-products. It does,
though, have its scrap products, The treads of tires
wear down, the soles of shoes become thin, but both
articles still contain a large proportion of vulcanized
rubber. By getting rid of the sulphur, can we recover
the rubber? Here lies an attractive problem for chem-
ists and inventors. Because the shoes, tires, hose,
belting, water-bottles, and other types of rubber goods
are partly oxidized, somewhat hardened, broken, and

RECLAIMING WASTE 89

impreg:Dated with sand, the enterprise is difficult.
Where the tire has rusted against the metal rim, it
contains cakes of hard mat. The scrap-pile is cer-
tainly unattractive.

At the beginning of this scrap industry, your old
tire case is sold to the dealer at about half a cent a
pound. He throws it into his back yard. After he
has accumulated enough of them, a junk dealer comes
along and buys these old tires from him. What fun
it used to be to gather old junk and trade with the ped-
dler! In the back country he was an integral part of
life. He came about with his load of pots, kettles,
pans, and brooms, and traded with us for the old rags,
old gum shoes, and other used-up products, which he,
as in the present day, sorted according to grades that
he knew would have more 6r le^s market value.
Finally the junk was shipped't'o the dealer who handled
larger quantities; be, in turn, sold it to the factories,
where it could be worked up into new products. In
the same way our old hose, our tires, and our rubber-
ized shoes are collected now. The business of buying
rubber scrap and selling it to the reclaiming mill is one
of considerable proportions.

In a consideration of what to do to bring this rubber
into usable condition, we are at once faced with a
fundamental fact: most rubber articles contain cot-
ton fabric in some form, others contain wool, and
a few, linen. It is a relatively small proportion of the
total tonnage that is free from fabric of any kind.
Now, this fabric is weakened by the service it has
nndergone: in many eases, it has been wet and is
partly decayed. It therefore has little value as fabric

THE BEIGN OF RUBBER

or as cotton. In any event, whether it is good or bad,
the fundamental problem is to separate the vulcanized
rubber from it. The first operation necessary before
these old articles can be put through any process, is
to free them from foreign materials, such as sand
and metals. Rubber mixtures must be clean and free
from any bard materials.

Consequently, in the reclaiming factory all material
is first sorted into classes, such as tires, shoes, and hose.
After sorting, each of them is finely ground. In the
course of this fine grinding, which consists of two or
three separate steps, the tire is passed over screens
and over a piece of apparatus known as a magnetic
separator. Here the slow-moving ground mixture of
vulcanized rubber and fabric is allowed to drop in close
proximity to a magnet, which deflects tbe iron particles,
causing them to fall off by themselves, and freeing the
rubber from the metal.

Tbe next step is one that has to do primarily with
the removal of fabric. In the old days, each little
rubber factory utilized what scrap came to it in its
own way. It was difficult, if not impossible, to re-
move fabric except by the so-called mechanical method.
This removal was accomplished by grinding the rubber
and blowing tbe fabric in finely-divided form out of
the mass by means of an air-blast. The rubber was
then subjected to the action of live steam at relatively
high heat; the resulting product became known as
"shoddy." This process left much to be desired. In
the first place, because more or less ground rubber
adhered to the particles of cotton and were blown
away with it, the yield was low. In the second place,

RECLAIMING WASTE

some of the fiber always remained .with the rubber
and accordingly made its appearance in the finished
product. In other words, the "ahoddy" was not clean,
and it was not much more than a filler.

The first attempts at the use of old rubber are said
to have heen made many years ago. From 1865 to
1870 but few people used old rubber. One company
sent old shoes to the women in the country, who tore
them apart by hand. They were paid by the pound for
aU clean rubber that could be stripped from the cloth
in the shoes. At this time Austin Day of Ansonia,
Connecticut, commenced to grind rubber, using at first
car springs and afterward old shoes.

Since in 1871 there was a demand for rubber free of
fiber, E. H. Clapp hit upon the method of subjecting
the ground material to an air-blast, the process separat-
ing fiber and rubber. For several years this method
was used, A number of men, though, tried to free the
rubber from fiber more completely. Much secrecy sur-
rounded factory practice. Rubber men, like snails,
preferred their shells; therefore who really discovered
first the acid process may never be known. But it
takes more than dreams and secret chambers to bring
about commercial results.

Lieutenant-Colonel Chapman Mitchell, a younger
brother of the eminent physician and author, S. Weir
Mitchell, after the Civil War went into the sugar busi-
ness with Harrison, Havemeyer & Co., in Philadelphia.
He had a keen perception. Accosted in the street one
day by a friend, he was handed some unoured mackin-
tosh clippings. Could he get the rubber back without
injuryT He saw a future and experimented, and a

92 THE BEIGN OF EUBBEB

new industry in the reclamation of rubber waste was
born. This was in the early eighties. The finely
ground mixture of rubber and cotton was immersed
in dilute sulphuric acid and steam was blown into it
through lead pipes, the steam warming it to the tem-
perature which permitted the acid to attack and destroy
the cotton. As the chemist would say, his process hy-
drolyzed the cellulose into a form soluble in water.
After the cotton was destroyed, the entire mass was
removed into a wooden circular tub or washer with
a large rotating wooden wheel in the middle, so de-
signed as to permit the wheel to churn the mixture in
water. After it was partially washed in this big vat,
the entire mass was allowed to flow down an inclined
wooden chute called a riffler, which contained cross-
pieces or baffles about two to four inches in height
and spaced about a foot apart. The heavy particles of
sand subsequently removed, would collect against these
slats ; while the rubber would run on down the riffler
into a settling tank. This was a sort of adaptation
of the metallurgical ore-washing methods.

After this washing process the rubber was in a con-
dition of relative fineness, although it was still not fit
for use; for it was firm, tough, vulcanized rubber,
free from cotton. The acid process part of it, there-
fore, was simply a cotton remover. Consequently,
the rubber men conceived the idea of placing the
rubber in trays, in a large open cylindrical tank,
about six feet in diameter and twenty-five feet long,
made of heavy boiler-plates and known as a devulcan-
izer. When the rubber was put in these trays or
placed in the devulcanizer in mass, steam was forced

RECLAIMING "WASTE

into the tank. The rubber was heated usually to
a temperature around 300° Fahrenheit and for a
length of time depending upon the type of scrap to be
heated. Frequently oils, to assist in the process, were
mixed with the vulcanized rubber before placing it
in the devulcanizer. The action of the high tem-
perature served to soften the rubber. There was no
rranoval of sulphur: in point of fact, vulcanization
went on a little further; but in the presence of steam
and oil, the rubber became plastic enough to permit
its final mixture with fresh rubber. In time, devulcan-
izang usually lasted about twenty-four hours. After
devulcamzation the rubber was removed, dried in air
driers, massed on a mixing mill, and thus prepared for
reworking.

An acid process from which nothing ever came had
been patented in 1863 by C. H. Hayward and D. E.
HajTvard of Massachusetts. Colonel Mitchell, how-
ever, made the process work, and continued in the in-
dention of apparatus until 1889. He instituted a com-
mercially efficient process and organized an industry,
for his company, the Philadelphia Rubber Works, was
ihe first commercial enterprise which had exclusively
for its purpose the recovery of rubber in the form of
the usable product that we call reclaimed rubber.

Because the Mitchell method was particularly applic-
able to the treatment of scrap in a relatively low state
of vulcanization and containing no free or uncombined
sulphur, it was effective with old boots and shoes.
The soundness of the process is evidenced in the fact
that even to-day it is still the standard method of
treating boot and shoe scrap. But since hose, belting.

THE REIGN OF RUBBER

possesses all the necessary properties of crude rubber;
for other purposes, it is vastly better than crude rub-
ber. Owing to a slight alkaline character that adds to
the length of life of the rubber mixture, it has an ad-
vantage. Thus has developed reclaimed rubber, no
longer shoddy.

Chemists and inventors, trying to reverse the vnl-
canization process, and attempting to split off the sul-
phur atoms in the vulcanized rubber molecules, called
the process "devulcanlzation."

One could scarcely wade through the mass of patent
literature. There have been many hundred patents
taken out on different modifications of the alkali proc-
ess alone. Numerous other substances have been
and still are used in connection with it, to soften and
give other valuable properties to the resulting mixture.
But the basic principle has never been modified and
is to-day the one process by which the greatest ton-
nages of rubber scrap are reclaimed and made usable.

Extremely interesting are the methods by which men
have attempted to dissolve vulcanized rubber in va-
rious solvents in order to remove the sulphur. I have
in front of me a list of 156 different substances that
have been tried, either to dissolve or withdraw the sul-
phur; they have all failed, and to-day the removal of
sulphur from vulcanized rubber is probably one of the
great unsolved problems in the rubber industry.
Perhaps some of these processes do definitely take the
sulphur out; but when the sulphur is all removed, the
substance left is not rubber but an oil. Rubber is so
complex, its affinity for sulphur is so strong, that any

EECLAIMING "WASTE

known reagent powerful enough to remove the com-
bined sulphur makes the rubher unfit for commercial I
a Be. '

The development of the Marks process resulted in a
large increase in the use of reclaimed rubber by rub-
ber manufacturers. By re*arch in the last twenty >
years and by perfecting a product that performs a def-
inite function in the rubber compound, the reclaiming
industry has eliminated shoddy. Redaimed rubber
has brought about a saving in mixing time and costs ,, .
and also a decrease in the time of cure. That its use
is fundamental in the manufacture of rubber goods has
been clearly demonstrated in the last year by the fact
that the production of reclaimed rubber has been in
approximately direct ratio to the production of the
classes of goods in which it has been used. The in-
dustry to-day rests upon the Mitchell patent and the
Marks patent. Scores of other patents haVe been
granted, but the processes have lacked some essential
feature; either they were too expensive, or the agent
used caused the rubber to deteriorate, or the resultant
product was not so good as that already on the mar-
ket. This does not mean, though, that future develop- ^_
ments may not be as revolutionary and sound as the ^^M
two patents already mentioned. ^^M

For the year 1921 the amount of crude rubber used
in the United States was 345,599,000 pounds, and of re-
claimed rubber, 76,508,000 pounds. It is an article of
tremendous importance and necessity in our economy. ^^9
There is no question of its value; articles made from ^^M
^iL^e well. Like any other material used in this com- ^^H

THE REIGN OF RUBBER

plex and intricate industry, though, reclaimed rubber
is one that requires a knowledge of it and of the pur-
pose for which the resulting article is intended, in
order to make its use justified. Even raw rubber
must be used with some degree of care.

Reclaimed rubber, therefore, plays a large and val-
uable part. Just stiff enough when in an unvulcanized
condition, it makes manufacturing of many articles
more easy. Reclaimed rubber is not used where the
maximum tensile strengths are required, any more
than pure crude rubber alone is used where toughness
or resistance to abrasion are required. For the tough,
resisting senace in a rubber heel, in footwear, in rub-
ber bumpers, in wire insulation, in carriage cloth, re-
claimed rubber serves, and serves well.

Many people seem to feel, usually without a knowl-
edge of the facts, that reclaimed rubber is not a val-
uable material for use in rubber mixtures. If it were
not used, there would be a tremendous waste that rub-
ber users should not sustain.

If this little story frees the reader's mind from any
idea that reclaimed rubber ia something inferior, it
would be well. Reclaimed rubber is not inferior ; it is
just different. It is true that one can make inferior
products from the best of materials; therefore in the
handling of reclaimed rubber, intelligence is required.
That during the period of low-priced crude rubber so
large a tonnage of reclaimed rubber has been used is
one of the best arguments in favor of its value and
quality.

The utilization of scrap rubber through reclaiming
is an economic achievement.

CHAPTER VII

THE CHEMISTRY OF RUBBER MIXTURES

This is a chapter of details. But chemistry is a
science of details, of little things, of explanations.

In Malaya we could go into the orchard and gather
a quart of milk from a rubber-tree, and then bring it
back to the laboratory and ask the chemist to look it
over. True to the habits of his kind, he would say,
**I know what that is, and how it is put together.''
He would know only some facts and theorize on the rest.

As it runs out of the trees, the latex is a milky fluid
consisting of water in which are suspended minute
globules of rubber. These globules are solid, not
liquid. Very fine in subdivision, they measure from
five ten-thousandths to three ten-thousandths of a milli-
meter. It is stated that they are so numerous that
one gallon of latex contains more than two hundred
billion of them. If we were to lay out these little glob-
ules side by side, we should find that those in one
gallon would make a minute rubber thread 372 miles
long. When observed under the microscope, they seem
to be somewhat irregular in shape. Since they are
solid, we term the latex a suspension of solid particles.
If the rubber were liquid, we should call the latex an
emulsion. Milk as it comes from the cow is an emul-
sion.

^^^^^^

THE REIGN OF RUBBER

When the chemist analyzes the latex, he discovers it
to contain on the average 28 per cent, of the chenaically
pure rubber; resins, which are substances soluble in
the chemical known as acetone, 2 per cent. ; mineral
substance from 0.3 to 0.7 per cent. ; components con-
taining nitrogen, which the chemist calls by the general
name of proteins, 1 to 2 per cent. ; sugars dissolved in
the water of the latex, 1.1 to 2.3 per cent.; and water,
about 60 per cent. From the latex may be obtained
30 to 35 per cent, of commercial raw rubber, which
contains various of these substances.

Proteins or nitrogen substances play an important
part in the latex. Modern chemistry has learned how
small quantites of them assist in the formation of
emulsions and suspensions because they seem to pre-
vent the separation of the emulsified substance from
the water. When you buy eod-liver oil as a medi-
cine, as most people do at one time or other, you
see a nice white emulsion. It would be quite
possible for the druggist to make you an emulsion of
cod-liver oil by the simple process of shaking together
the oil and water; but, on standing in the bottle, the
oil would separate in a layer by itself. Physicians
have found it wise to give cod-liver oil finely divided
with water in the form of an emulsion, because it di-
gests readily. In order to keep the preparation, there-
fore, from separating into two layers, casein is added
to it, which has the peculiar property of protecting
the globules of oil and keeping them away from each
other.

Nature has prepared for us a suspension in which
she has put in a substance, namely, the protein, that

CHEMISTRY OF BUBBEK MIXTURES 101

permits a high degree of dispersion of these fine par-
ticles and prevents their rapid coalescence into a layer
separate from the water. The substances that play
this part in preventing the coalescence of snspended
or emulsified globules are known as protective col-
loids. Different rubber-trees seem to have different
protective colloids. Because the latex of the Hevea
tree is very stable, the rubber from it does not tend
to separate or float to the surface in the form of cream.
The latex of the African trees and the latex from the
Central American trees seem to have in them differ-
ent protective colloids; for, on standing, the rubber
floats to the top.

A gallon of latex weighs 8.17 pounds and contains
from 2.45 to 2.85 pounds of raw rubber. To supply
the world with 250,000 long tons of rubber requires,
therefore, in the neighborhood of 224 million gallons
of latex. The difference in composition between rub-
ber latex and milk is striking, for the cow has nothing
like the efficiency in production of the substance most
desired from it, namely the fat, cow's milk showing
only 3 to 6 per cent, of butter fat. These two milks,
the vegetable milk and the animal milk are, therefore,
radically different.

On the plantations, it has become necessary to handle
latex as rapidly as possible, — in any event, to limit to
certain reasonable and well-known lengths the time be-
tween its collection at the tree and its coagulation in
the shed or factory, because as soon as it comes into
the air from the tree it begins to decompose and to be
acted upon by bacteria. Coagulation, the change that
is required chemically in the latex, is the alteration of

102

THE BEIGN OF EUBBEB

the protective colloid. The addition of acids changes
the latex in such a way that the proteins are no longer
able to prevent the globules of nibber from running to-
gether. The first step in the chemical change of latex
is to add acetic acid in dilute solution. It is used
in dilute solution because the quantity of protective
colloid is small and but little acid is required to alter it.
Strictly speaking from the chemical point of view, the
nature of its alteration is unknown. It is evident,
though, that acetic and other acids will cause coagu-
lation.

We know that when latex is allowed to stand it grad-
ually becomes acid from the action of bacteria on the
proteins; just as when a glue and water solution is
allowed to stand, it changes to acids through the
action of bacteria and fungus growth. By any kind
of coagulation, though, the rubber itself is not changed ;
the little particles that were held apart in the water
solution simply mass together.

If latex is allowed to coagulate spontaneously, a dis-
agreeable odor develops, which persists until vulcan-
ization. When coagulation occurs by acetic acid, how-
ever, the rubber is odorless. Although other acids,
such as formic acid and sulphuric acid, have been used,
more than 95 per cent, of the raw rubber is now
prepared on the plantations by the use of acetic
acid. It in no way injures the quality of the raw
rubber.

Let us now turn to the raw rubber itself and exam-
ine the facts that chemists have learned regarding its
characteristics and properties. The first and most im-
portant one is the variety of substances contained in

CHEMISTRY OF RUBBER MIXTURES 103|

it. Rubber itself, free from these substances, is a hy- 1
drcicarboii. An interpretation of this chemical term I
means that it is composed of only the chemical ele-
ments carbon and hydrogen. Raw rubber contains i
from 92 to 94 per cent, of the rubber hydrocarbon. Be- I
sides this, it contains moisture, mineral substances,
resins, — which are simply a variety of chemical in-
dividuals soluble in acetone,— and the proteins. The
composition is about the same as that of the latex, with
the water and the ingredients dissolved in the water,
or serum, removed.

In the laboratory the chemist, who with beaker and
combustion furnace analyzes the hydrocarbon, finds it
to be made of five carbon and eight hydrogen atoms.
But there are several other hydrocarbons that show
the same constituents on analysis. The rubber hydro-
carbon is a distinct one. Therefore he has come
to believe that several of these CoHg groups are united
physically (he says "polymerized"), and he expresses
the composition (CbH;,),.

But the chemist is a singular fellow. He has learned
that the terpenes, of which turpentine is one, have a
composition CidHig. So he calls rubber (CioHis).
Among his technical friends, he goes further and
draws a picture of the hydrocarbon, in which the ex-
act relation of each element to the other is shown.
Since the chemist loves these pictures, we shall leave
them to him. They belong to the moat intricate field
of organic chemistry, and the rubber structure to the
most intricate of them all.

Rubber may be made artificially by heating the oil
"isoprene." The chemical process, which consists

■

sists ^H

104 THE REIGN OF RUBBER

in the addition of one molecule to another, forming a
snceession of these groups linked together into a ring
of uncertain dimensions, we call "polymerization."
How far the chemical compoBition, the state of poly-
merization, or the state of aggregation of the poly-
merized maBses, affects the properties of crude rnbhex
as we know them, and how far the hydrocarbons from
trees of various ages differ chemically and physically,
arc all unknown phases of an interesting problem.
We do not know the part played by mineral substances
or the exact condition of the nitrogenous matter, al-
though the proteins have a most important influence
upon the characteristics of the rubber.

The other substances in raw rubber after coagulation
are not deleterious impurities. They are of wonder-
ful advantage by assisting in resistance to oxidation
and by helping in vulcanization.

To determine the percentage of acetone-soluble mat-
ter, much study has been done by some chemists in the
analysis of rubber. Rubber from different botanical
species varies largely in resins. The plantation rub-
ber coming from the Hevea tree seems to produce the
smallest amount of any. The Ceard rubber, the Ficus
rubber, that is, those from Central America and Af-
rica, on extraction in acetone yield resinous matter as
high as 7 to 10 per cent. The guayule rubber shows
20 per cent, of a liquid resin. Lower grades, such
as the scrap, the rubber that has fallen upon the
ground, and those grades that have been allowed to dry
in the bright, hot sunlight, seem to have decomposed
a little; as a result, the amount of substance to be ex-
tracted by acetone has increased. The rubber resins

CHEMISTRY OF RUBBER MIXTURES 105

are highly complex, and whether they are the original
source of mbber in the tree or whether they have been
produced from the rubber we do not know. Probably
to-day the * * acetone extract ^ ' is the one reasonably re-
liable means of determining the botanical origin of
different grades, and the fresh from the deteriorated
rubber; although the control of quality in a finished
article can be carried on irrespective of the origin of
the rubber. The amount of resin extracted by acetone
is not, as some have believed, a guide to the quality of
a vulcanized rubber mixture.

A chemical property of the rubber hydrocarbon is
nnsaturation. It adds directly halogens, halogen
acids, sulphur, and sulphur chloride, as well as certain
other substances.

The story of synthetic rubber has been much dis-
cussed. Artificial rubber is well-known. During
the World War much work was done upon it in Ger-
many, where considerable quantities were produced;
but it was not the same hydrocarbon as that derived
from the tree. It was a close relative, known as methyl
rubber. But the tires and other soft rubber articles
made from it were decidedly inferior in service. It
was, however, valuable in hard rubber or ebonite.

After its coagulation, one can think of rubber as a
body made up of innumerable round globules of rub-
ber in the form of a sort of microscopic mass of fine
shot, each of which is surrounded by a thin film of pro-
tective colloid, the protein substance. Thus, raw rub-
ber has a structure. It is not like glass, which is homo-
geneous; not like leather, which is a mass of fibers;
or like wood, which is a mass of short, thick fibers.

THE EEIGN OF EUBBER

The probability of tliis stmcture is interesting!]
proved by the action of rubber when it is softened ol
masticated, as we call it, on a mixing mill. If our
theory be correct, some of the toughness of rubber in
its raw ^tate is due to the harder nature of the sur-
rounding protective colloid. The use of this term,
protective colloid, when one is speaking of rubber in
the mass is not exact; for it really is a protective col-
loid only when the rubber is dispersed through the
latex. Nevertheless it still surrounds the particles of
rubber. These proteins are probably stiff like glue;
because when masticated on a mixing mill, the rubber
becomes softer from the breaking up of a certain
amoimt of this structure. After prolonged masti-
cation, it is not 80 tough as before.

The rubber, when mixed, is passed through a ma-
chine known as a calender in such a way that it issues
in the form of a thin sheet. Even after vulcanization,
the rubber is found to show a difference in strength in
the direction of the passage through the calender from
that at right angles to it. For years the rubber man
has observed this property, which is known as "grain."
It is quite possible that the little rubber particles are
stretched during the process of calendering, so that
we may imagine them in the form of elongated fibers
very minute in size, rather than as little spheres.
Since they probably overlap each other in somewhat
the same way as fibers of cotton during the twisting
of cotton fiber into thread, one may readily picture
them a series of little rubber threads, naturally tougher
in the direction in which the fibers have been stretched.

In another way we have proved that there is a struc-

CHEMISTEY OF EUBBER MIXTURES 1071

"e in rubber, which structure is changed and broken
the process of mastication. Raw rubber, in a sense,
iS not dissolve in solvents. One may say, rather,
it the solvents dissolve in rubber. If a piece of
Ibber is allowed to stand several hours, for instance,
benzol, in gasoline, or in carbon bisulphide, it swells
'.several times its original size. The solvent has,
ifore, penetrated and dissolved in the rubber,
however, in the regular course of cement mak-
ing, the rubber is beaten or stirred so that mechan-
ical action is applied upon it, a cement is obtained
which is really a distribution of the swollen and soft-
ened rubber in the balance of the solvent that has
been used; that is, a colloidal solution has been ob-
tained. The difference between a colloidal solution
and a true solution lies in this fact; a true solution,
such as salt in water, is one in which the solid has
passed into the liquid in such a way that the proper-
ties of the solution are homogenous.

When we make this colloidal solution in benzol, us-
ing only 2 per cent, of rubber that has never been
passed through between the rolls of a mixing mill, and
compare that with a liquid of the same strength but
which has been softened or masticated by a mixing mill
for about twenty minutes, we observe a distinct differ-
ence. The solution that contained unmasticated rub-
ber is thicker and more viscous than that containing
tbe masticated rubber. This has led to a belief in raw
mbber structure, which structure has been broken
down by mastication, so that the little films of pro-
tein are broken up and distributed into the rubber
mass. Just what the structure is, what it means, and

THE REIGN OP RUBBER

how to change it, are problems yet to be solved by the
research chemist.

After all, what is vulcanization t Ever since the
discovery of the process, chemists have worked upon
this question. There are numerous theories. One
thing we do know, fiowever, that sulphur in some way
actually combines with the rubber molecule. Rubber
has an affinity for sulphur ; and once it has taken enl-
phur on, there is no divorce court known that can
separate them. Probably divorces never leave the
parties thereto in just the same mental state; there-
fore, while by drastic chemical methods sulphur has
been removed from rubber, the rubber is never the
same in physical properties as it was before its union
with sulphur. When only about 2 per cent, by weight
of sulphur is added to rubber, it serves to produce a
soft, strong, stretchy composition. During a study
of the basic principles of vulcanization, when a sample
of rubber containing 10 per cent, of sulphur was
heated even for a long period of time, all the sulphur
did not combine. Some of it remained as free sul-
phur. Investigators analyzed samples regularly over
a period of several hours, and found that the sulphur
combined with the rubber steadily. There is no chem-
ical compound formed during the vulcanization of soft
rubber ; the process is continuous. The amount of sul-
phur that enters into combination with rubber in-
creases with time and rise of temperature; when the
time and temperature are constant, the amount of sul-
phur entering into combination with rubber is depend-
ent upon the quantity of sulphur originally present.

Once it was believed that sulphur did not combine

CHEMISTRY OF EUBBEE MIXTURES 109

irith rubber nntil the temperature had passed the melt-
ing point of sulphur ; but this was definitely disproved
a few years ago by a chemist who permitted a mix-
ture of rubber and sulphur to stand at relatively low
temperatures, one sample at 122° Fahrenheit, over
periods of days up to eighty. He found the same
regular combination of sulphur with the rubber. So
vulcanization does go on at ordinary temperatures,
but slowly.

When small amounts of about 3 per cent of sulphur
are combined, as we say, with rubber there results
the soft rubber of commerce. During the time of
heating, while the essential process of vulcanization
occurs, all the sulphur is not combined; there is an
excess called **free sulphur. *' Shortly after the rub-
ber is removed from the mold at the end of the vul-
canization, the color at the surface is that of the
mixture itself. When the rubber stands for a little
while, however, an interesting change takes place;
for this excess sulphur, or **free sulphur, '^ begins
to crystalize and separate itself from the rubber.
Probably dissolved in the rubber during vulcan-
ization, on cooling and standing it separates. At the
surface, we find it coming out in the form of a gray
powder called *^ bloom.''

Essentially all rubber articles show bloom, or ** sul-
phuring up,'' on the surface. To be sure, there are
some of them such as boots and shoes and colored
water-bottles wherein a freedom from this gray powder
is desired. It is very difficult for the rubber chemist
so to design his composition that bloom will not occur.
In doing this, in order to combine all the sulphur, he

DHEMISTEY OF RUBBER MIXTURES 111

tances or the incorrect proportions into her bis-
I, she bakes soggy ones. If she leaves them in the
. too short a time, they are underdone. Likewise,
e rubber man removes his mixture from the press
the mold too soon, he finds the rubber to be weak,
^what sticky, or, as he calls it, **undercured/' If
aves it in the right length of time (there is a large
ay usually), he finds it strong, not tacky, and resil-
If he leaves it in too long, it becomes like over-
I roast beef, dry. On breaking, it is found to be
t, that is, it breaks at a shorter elongation than it
Id. He calls it * * overcured, ' ' or he says it is
led. By long, sad experience, he has also learned
it does not age well, but gradually becomes harder
harder, taking on oxygen from the air with much
ter rapidity when over-cured than when either
)r or correctly cured. The time and temperature
ire for each composition, or the adjustment of the
position to cure at a time and temperature for
3 factory practice, is one of the most essential of
rubber chemist's duties.

lere are wide and, to the manufacturer and con-
3r, vitally important differences in physical prop-
is between under-cured, properly cured, and over-
d rubber articles. Still we have as yet only the-
i of a general character to explain the nature of
3 products of vulcanization. The amount of com-
3 sulphur, when expressed as a percentage figure
jrms of rubber as 100 per cent., is known as the
Icient of vulcanization. No chemical individual
le rubber hydrocarbon and sulphur has been iso-
l from soft, vulcanized rubber mixtures.

112 THE REIGN OF RUBBER

When a large excess of sulphur is used in a mis-
tnre, addition goes on up to a maximum of 32 per cent,
of combined sulphur; and there results the only chem-
ical compound that yet has been isolated — a mono-sul-
phide CsHgS, or, as usually written, CioHieS^. It is,
in the laboratory, a brown, dry powder. In the factory
and in commerce we know it as hard rubber or ebonite,
used in battery jars, sheets, fountain-pens, and the Uke.
It is highly resistant to the action of chemicals. Around
hard rubber has developed a sort of separate industry,
to be discussed in a later chapter. It is a rubber in-
dustry, to be sure, but an industry wherein stiffness,
strength, freedom from action of chemicals, and a high
degree of resistance to penetration by electrical
charges are required.

Many discussions have arisen between two camps of
chemists; those who expound the sulphur absorption
theory of Ostwald and those who stand by a chemical
theory. The great rubber chemist Weber was an ex-
ponent of the chemical theory. Chemists to-day ad-
here to a combination of a chemical and physical the-
ory as most reasonable for the explanation of vulcan-
ization. The fact that no compounds have yet been
isolated in the soft rubber range of vulcanization is no
reason for us to believe that a purely physical theory
alone will account for it. Carl Otto Weber will ever
remain in the minds of rubber chemists as the most no-
tabls leader. Born in 1860, of German-Scotch ances-
try, he studied chemistry in Germany and migrated to
England, where for some years he was a managing
chemist in a rubber factory. A prolific contributor to
technical literature, an indefatigable research chemist,

CHEMISTET OF RUBBEE MIXTURES 115

f CHEM]

f of sulphur in a very active or, as the chemist calls it,
' nascent condition. It is so active, in fact, that it adds
itself to rubber very easily at room temperatures, giv-
ing thus a process of vulcanization that is different
from any of the others, although the basic principle ia
that of addition of sulphur to rubber. These processes
are being worked out in England and, to a degree,
in this country; but they have not yet become a large
factor in our rubber markets.

The most striking advance in the chemistry of vul-
canization has been made with the use of organic ac-
celerators. The first inorganic accelerator was white
lead, used by Goodyear in 1839. The chemistry of this
type of accelerator, so far as known up to recent years,
was that of the old idea of the carrier. Serving to
attach to itself sulphur, and thou letting go of it,
white lead gave the sulphur to the rubber in a shorter
time than the rubber could take it up alone. Without
knowing exactly the condition in which the sulphur was
when given to the rubber by white lead, the chemist
supposed, in any event, that the sulphur was made
more active by the use of this catalyst.

With the coming of the organic accelerator, many
chemists have tried to find out exactly why it acts
so rapidly. Despite the large number of these organic
substances, the idea was prevalent for some years that
only those containing nitrogen were sufBciently power-
ful for practical use. Thus, the derivatives of aniline,
or, as it is known to the chemist, aminobenzene, were
employed, and various more intricate modifications and
derivatives of aniline. Lately, however, chemical com-
pounds that contain sulphur have been employed.

116 THE REIGN OF RUBBER

These facts have led chemistB to search for the cause.
To make a long story sufBciently short, these investi-
gators have learned that vulcanization occurs most ac-
tively when the accelerator first adds sulphur to itself,
and then separates off the sulphur in a particularly
active condition. The accelerator with its extra sul-
phur chemists call a polysuiphide. It acts like a dump-
cart — quickly loaded, quickly unloaded.

The real chemistry of the properties possessed hy
vulcanized rubber when in contact with oils such as
benzol, gasolene, or heavier lubricating oils, is not
known. Kaw rubber absorbs these oils and swells;
vulcanized rubber likewise absorbs them and swells.
Some substances cause vulcanized rubber to swell more
largely than others ; and some cause vulcanized rubber
to shrink. Methyl alchohol, wood alcohol, or grain al-
cohol will shrink vulcanized rubber slightly. Some
substances produce no change. The derivative of ben-
zol known as toluol swells vulcanized rubber slightly;
benzol swells it to nearly double its size, but car-
bon bisulphide to more than double. But this swelling
is the end of the effect; it is not possible by heating or
by any other method to make vulcanized rubber into
a colloidal solution. Oiled roads, therefore, are not
particularly good for tires.

In an earlier chapter we have considered powders
and their effect in rubber mixtures. Why do these
substances act as they do? It is a most interesting
question, and one that is probably not yet wholly
solved. Let the microscope tell its story. An exam-
ination of the photomicrograph of zinc oxide and some
other substances used in compounds shows these sub-

CHEMISTRY OF RUBBER MIXTURES 117

stances to be very small. It is doubtful whether the
ultimate particle of carbon-black has ever been seen
under the microscope. It is probable that the larger
particles shown are aggregations, and that even the
smaller ones may be minute aggregations. When the
microscopist measures these, he observes as closely aa
he can the particle-size expressed in diameters, as
though these little particles were spherical in shape.
The diameter of carbon black is less than two ten-
thousandths of a millimeter; that of zinc oxide
is about five ten-thousandths. Other dry pigments
are all larger in size. Not only do the photo-
graphs show the particles of carbon-black and zinc
oxide to be finer in size than those of the barytes, but
they vary in structure and do not seem to have the
sharp angles and faces evident in the barytes. Here
the chemist has made good use of the microscope, as
you see in the photographs.

These finer-grained materials may be classed in two
groups : finely divided colloidal particles and all others.
Colloidal particles are those of gas-black, zinc oxide,
lithopone, some grades of clay, magnesium carbonate,
and many others. The "all others" include barytes,
asbestine, whiting, and a large number of mineral sub-
stances. There is no clear line of division between
these groups, except in the process of manufacture,
the size, and the specific action in a rubber mixture.
After all, rubber, as the consumer gets it, is not a sim-
ple mixture of rubber, sulphur, accelerator, zinc oxide,
and carbon-black ; but, to meet the demands of numer-
ous physical properties required for service in the
form of shoes, adhesive layers, treads, and belt covers,

I
I

THE KEIQN OF RUBBER

other materials most be used. We have foond in re-
cent years how these materials serve practical pnr-
poses and are not simply cheapening fillers. In point
of fact, many powders now cost more than crude rub-
ber. The mle-of-thumb methods are gone from the
leading laboratories, but the variables are so extended
that the service test has become the final criterion of
the value of any mixture.

While we have developed research laboratories to
show U8 why, development departments to show us
how, testing machinery to give us results, we, never-
theless, are constantly faced with the question: Will
rubber age! Rubber is a perishable product. For any
purpose, a knowledge of the rate of deterioration is
most advantageous, because the problem is a vital one
to manufacturer and consumer. Heat, light, oxygen,
and sulphur play their parts in the tragedy; but, as
yet, no definite theory to account for the varied rate of
aging has been proposed. In the vast majority of
eases, too rapid decay is due to over-cure of the mix-
ture, or improper conditions of storage. Differing in
practice from that of the old days, chemists have de-
termined means of testing the rate of aging. Various
types of apparatus have been developed, until to-day it
is possible within a space of two weeks to predict
fairly confidently the length of life of any given compo-
sition; at least, the prediction can be made by compari-
son with compositions of a known length of life.

All rubber goods should be stored in the dark and
kept as cool as possible. Both these factors are under
the control of the user. Even though the rubber chem-
ist makes his compositions the best he can, it still is

CHEMISTRY OF RUBBER MIXTURES 119

necessary for the consumer to cooperate with him by
keeping away these two active forces, heat and light, if
he, the consumer, desires to maintain his rubber prod-
ucts for the maximum time. How long should they
remain strong and serviceable! That depends upon
storage conditions, because over-cure has pretty gen-
erally disappeared. In hot climates one should expect
trouble; under temperate and cold conditions, very
Uttle.

CHAPTER VIII

THE BICYCLE TIEB

Wheo Nancy Hanks in 1892 trotted a mile in 2:04
and clipped over four seconds from the best previous
record, she not only established a mark for horse rac-
ing, but she earned a place in the hall of rubber fame.
For the first time in history, pneumatic-tired wheels
were used successfully on vehicles other than bicycles.
She drew the bicycle-wheeled sulky. Her performance
announced to the world that pneumatic tires on wheels
were speedy. In a few months the steel tires disap-
peared from sulkies and the solid tires from bicycles.

As the forerunner of the automobile, the bicycle ex-
pressed a human desire for faster and more comfort-
able transportation. The history of the bicycle be-
gan in Germany in 1816, with the first vehicle upon
which man rode and propelled himself. A year or so
later, the old dandy-horse or hobby-horse was de-
veloped in England and introduced into America.
The bone-shaker (a descriptive name), driven by the
feet alone, and steered by hand, was exhibited in
Paris in 1865. It was a two-wheel velocipede with
foot cranks and two wooden wheels equipped with iron
tires. For several years this was quite popular, but
it was too uncomfortable to serve for long.

About 1870 C. K. Bradford suggested rubber tires,

THE BICYCLE TIRE

121

mi BO for a time solid, round tires were used.
By 1877 the tire had evidently given snfBcient relief
from discomfort to warrant the organization of the
Pope Manufacturing Co., to make bicycles with solid
rubber tires. Eiders shook themselves upon these
antil 1888, when John Boyd Dunlop of England, in an
attempt to satisfy the cravings of his small boy, in-
vented a type of tire that was the first practical ap-
ieation of the pneumatic tire. He had, to be sure,
antedated in principle, as he himself admits, by
;ral inventors, particularly Robert W. Thomson in
tKs idea of a carriage wheel as early as 1845. Thom-
»n, an Englishman, wished to make carriages easier
draw, noiseless, and more comfortable. He made
the first single-tube tire of several plies of canvas
covered with rubber — "sulphurized India rubber and
€aeh fold connected to the one below it by a solution
India rubber." He blew it up with air. The af-
fair was crude, but the inventor was far ahead of his
time.

Dunlop, a veterinary surgeon in Belfast, Ireland,
unlike Thomson, brought out his idea opportunely ; but
it might have been neglected, except for the foresight
of Du Cros, prominent enthusiast in Irish racing. Du
Cros organized the Dunlop Co., doing much to make
the Dunlop tire practicable. This is another one of
these instances where mere invention has not signi-
fied application. Many inventors are so far ahead of
their times that their work falls into the discard; and
it remains for others really to develop- the ideas and
put them on the market in form for real use and ser-
vice. That inventor who fits his work to an immediate

[

THE KEIGN OF RUBBER

beed and combines it with busioess acumen and mann-
factoring facilities is he who makes the greatest sue-
From Dnnlop down to the present, the bicycle
tire has been continually improved, filling the changing
needs of service.

This first Dunlop tire was an outer casing of several
plies of rubberized canvas, with means of inflation.
Bound about each of the wheels of a tricycle o\vned by
a young son of the inventor, it was held to the rim by
wrappings of tape. Thus the bicycle tire came into be-
ing, to fill the needs of youth. It was called the "pud-
ding tire" and was generally ridiculed. It was, how-
ever, faster on the road and more resilient than the
solid tires of that day. The patents granted resulted
in the formation then of one of the world's most im-
portant tire companies, the Dunlop Pneumatic Tyre
Co., Limited, of England. Living until October 23,
1921, Dunlop came to see his work and the company
which bore his name a tremendous success, and to see
his invention used on millions of bicycles and automo-
biles.

Tape wrappings to hold a tire on a felloe did not
last long enough. To improve them, there came sev-
eral inventors ; among them, Pardon W. TiUinghast, in
1892, with a perfected single-tube tire, a valve, and a
method of attaching the tire to the rim. He had vul-
canized into the form of an annular ring, an inner tube,
a supporting layer of fabric, and an outer wear-resist-
ing cover. He endeavored to improve Dunlop 's tire,
because he thought the tube would chafe against the
easing. His invention was put on the market under

THE BICYCLE TIRE

I the name of the Hartford Tire, manufactured by t
Hartford Rubber Co,

It is stated that the pneumatic tire factory of Geor®
t. Bidwell Cycle Co., of New York City, in April, 1893,
med out the first pneumatic tires on this side of till
l&tlantic.
Probably the one other patent of most interest is
wt of Thomas B. Jeffery of Chicago, who in 1892
!8eve!oped an improvement in form of a specially de-
I signed clincher tire of a double-tube character. He
worked out new means of securing the tire to the wheel,
of diminishing danger of puncture, and of preventing
a leakage of air that would occur with a puncture.
Even though the prevention of leakage was not highly
I BDceessful, the idea of a clincher rim was quickly taken
[Bp in cooperation with a Mr. GormuUy. The GormuUy
md Jeffrey tire, or the G. & J., as it was called, was
Kormany years one of the most prominent and widely
i types of bicycle tires. In fact, upon this clincher
1 principle as almost simultaneously developed in
France, the original pneumatic tires for automobiles
were based. Morgan & Wright of Detroit also in-
vented modifications of value.

In these years, the bicycle became increasingly pop-
niar, so much so in fact that many a rubber company
making tires may oe said to owe its survival in the
panic of 1893 to the popularity of this means of loco- '
motion. Tire making progressed rapidly in Europe
simultaneously with development in America.

In England in 1893 the original pneumatic tire made
by the Pneumatic Tyre and Booth's Cycle Agency,

124 THE REiaN OF RUBBER 1

Limited, and commonly known as the "Dunlop" from
the name of the inventor, holds the place of honor.
Not only this, but the patents had been admitted by
nearly all the tire makers; and these were paying
royalty. The 1893 pattern consisted of an air tube
and an outer cover backed with strong canvas-
Through the edges of this canvas continuous wire rings
passed. These rings were smaller in circumference
than the edge of the rim, but greater than the center ;
and when the tire was inflated, they rested midway be-
tween the two and could not slip off. The tire was
fast, comfortable, and tough. Then there was the
Scott tire ; and next came the Michelin tire, which was
secured to a nearly flat rim by steel rings. The Sed-
don tire was another pattern. Another group of tires
may be described as the clincher variety, the cover be-
ing secured to the rim by the pressure of the air. The
clincher, made by the North British Rubber Co., was
the originator of this class. There were several
others.

The Philadelphia Cycle Show in February, 1893,
marked a turning point of moment in tire history, for
there the first cord tire was shown. The inventor was
John F, Palmer of Chicago, and the manufacturer, the
B, F, Goodrich Co., of Akron. He attempted to embody
a principle that secured the closure of any ordinary
puncture that might occur in the tread. But it did not
close punctures. Have we ever seen a tire that did?

Bicycles were soon everywhere. Bicycle racing be-
came a sport of parts. In Europe, where the automo-
bile development has not progressed in proportion to
population so rapidly as in this country, the bicycle

THE BICYCLE TIRE

is to-day seen upon the public road to a very much
greater degree than here. In France in 1921 there
were over 4,000,000 bicycles; in England, about
5,000,000; and in America' about 5,000,000.

The bicycle tire of the single-tube variety is made to-
day in largest numbers in America; in Europe the
double-tube predominates. A bicycle tire in the
United States is simply a tube, round in section and
circular to fit the wheel, made of several layers of light
fabric, proportioned to the degree of load that it must
carry, with an inside layer of rubber to hold air, an
outside layer of rubber to resist abrasion, and layers
of rubber between the plies of cotton to bold them to-
gether, and the whole thing vulcanized in one process.

If we were to go over into the bicycle tire department
of any of the several manufacturers, we should find
a process about like this : Frietioned and coated fab-
ric to make up the plies giving strength to the tire has
been previously prepared in the calendar room, where
compounds are used that experience has proved good
for the purpose. The rubber inner tube is laid
upon the bias-cut fabric. These layers are as long as
the circumference of the tire and as wide as the
length around the section of it. A little extra is used
to overlap or splice the edges and ends. The work-
man now overlaps and sticks the edges of tube and fab-
ric together from end to end around a -short, curved,
hickory form, while the fabric lies upon a sheet-iron
drum. Then he attaches the valve-stem, the form is
pulled out, and the opening closed. The outside rub-
ber parts, tread and side wall, are applied in sheet
form, after which process a drum a little larger is

120

TlfE EEIGN OF BrSBEB

pulled over tho now formed tire, and air is blown into
it to pniHH it between the drams. The oater dnnn by
n (|iiuik motion is pushed along the inner, an action
wliioh HorvoB to roll the inflated tire between the two
tlrnniH luul tliiiH force all parts to stick together.

'rh(< utivulcanizcd tire is formed In the same shape
fitut n'lw ill which it comes into the market. It is taken
io llu« vuIcfuiiziiiK or curing room, where it is laid in
n tw»ii>ttrt uiolii or doughnut of meta! that has been
h»«lloW(ni to the exact size of the outside of the tire,
tho vhIvp jirojecting out through an opening into the
tii<ti< ill Iho doughnut. The top of the mold having
ttttftn Itild oil, the mold is put into a hydraulic press,
wliwi'" proHMure upon the mold closes it. Steam is
thmi Hpplied inside the tire, inflating it against the re-
kU1hiu>» of the heated mold and causing the rubber to
(low iuto the markings that give form to the treai
lIuottUHO of the heat of the steam inside and the heat
of the mold from the steam in the press plates outside,
the ruhlier composition quickly vulcanizes.

This is the simple method of making a bicycle tire
tiomposed of square-woven fabric. There are, how-
evei', bicyolo tires of cord construction. The first cord
tirw, th(t Pahuer cord bicycle tire, showed so much
tfroater rcHilionoy than the square-woven fabric bicycle
tire thut many a race was won by means of it. It was
HI) uxptmsivo tire to build, for it was before the days
uf tlio conception of a loom-prepared fabric made of
noixl, Nowadays, cord bicycle tires are made from
IJiK namo typo of fabric, although lighter in weight,
thttt wt> umi in automobile cord pneumatic tires.
'I'luTii uro Hoveral different weights: there are those

THE BICYCLE TIRE 127

made of heavy fabric, suitable for all commercial and
utility purposes ; there are medium- weight tires, which
should be the choice of the average rider who uses
his machine for general purposes; and there are the
light-weight tires for the man who wishes to go at
the highest speed or to enter races.

Here, the quality of rubber and the construction of
the fabric make great differences in the resiliency and
speed. As in the case of all articles, the rubber chem-
ist designs his compositions each for a particular pur-
pose ; thus the tread is carefully worked out to give re-
sistance to abrasion, and the friction or layers of rub-
ber which hold the plies of fabric together are designed
to do that particular thing during the life of the tire.

The bicycle has come into our lives to stay. It is
a light, convenient little machine, which transports
people easily and quickly and at the same time gives
them some exercise.

But as the boy, so may the man become. The bicycle
tire prepared the way for the automobile tire. It set
men thinking, too, about good roads. We owe much
to Colonel Alfred A. Pope, who in 1893 sent out to the
newspapers a circular letter urging the people of the
country to petition Congress for the establish-
ment of a Road Department and Institute of Road En-
gineering. He was the pioneer in this country for
good roads. If the bicycle tire did nothing else it
stimulated highway construction.

CHAPTER IX
THE PNEUMATIC AUTOMOBILE TIRE

In China there was a horseless vehicle before 1600.
Vehicles propelled by foot and hand were known in
Europe in the seventeenth century. A French phy-
sician made a mechanical vehicle in 1710. Carriages
with sails were early known in England. The period
from 1800 to 1835 was a vastly busy one for steam en-
gineers, and about that time the steam vehicle be-
came fairly well established in England.

The old Hancock steam carriage of England, called
"the infant," making regular trips between London
and Stratford, was a forerunner of the modern in-
terurhan passenger bus. To its inventor prob-
ably should be given the distinction of making the first
passenger automobile in the world, because he manu-
factured for himself a steam phaeton, used extensively
about London, that was equipped with seats for three
persons.

Upon the internal combustion engine and the
experiments of Daimler, Benz, and Selden the
automotive industry to-day really rests. All the first
cars, and particularly the steam ones, lacked strength
and sturdiness; they jarred themselves to pieces in
a comparatively short time after being put into serv-
ice. To be sure, the metals were not so good aa

Courtesy of The B. F. Goodrich Cc.

THE PNEUMATIC AUTOMOBILE TIEE 129

those of to-day, for modem metallurgy is of relatively
recent development; but the main difficulty lay in the
vibration caused by bad roads and lack of cushioning.
True, the use of rubber for cushioning vehicles had
been planned by Thomas Hancock in England. That,
though, was before the days of vulcanization; conse-
quently his idea had no real value. It was therefore
the discovery of the art of vulcanizing rubber and the
making of tires from it that made possible the extended
development of the automobile.

In 1896 there were but four gasolene automobiles in
the United States: the Duryea, the Ford, the Haynes,
American ears, and the imported Benz. They were all
experimental machines; there was no market, and it
was 1898 before the first bona-fide sale was consum-
mated. Alexander Winton, who ranks almost with the
pioneers from the point of view of experimentation,
sold a one-cylinder Winton automobile; he received
payment for it and shipped the car April 1, 1898.
Curious old things, they would make as much of a sen-
sation on the road to-day as they did then, but for
quite a different reason.

The nest time one of your tires blows out or is other-
wise incapacitated for service, you might find it inter-
esting if, instead of passing it on to the Junk dealer,
yon would spend an hour in an examination of its con-
straction. Whether your tire be "cord" or "square-
woven fabric," cut a two-inch section out of it with a
sharp knife from tread to bead, so that the edges will
be smooth. Then saw the bead in two with a hack-saw.
There are three necessary parts of a tire : the casing,

THE REIGN OF RUBBER

miles, but permanently, because tbe rubber in the lay-
era between the cords is put in at the time of manufac- I
ture and stays there until the tire is gone. There is no '
other substance yet found that will remain so perma-
nent as vulcanized rubber under the heat and bending.
But the cotton is equally important with rubber; it is
the backbone of the tire.

The fabric of the so-called square-woven type is
manufactured by those operations generally used for
ordinary cotton cloth. That is to say, the fibers are
twisted into yam and the yarn into threads, and the
threads are then woven into cloth upon a loom. The
threads are of the same size, shape, and twist ; one set
known as "warp" is interwoven with another set
called "filling," and each runs under and over the
one adjacent to it. Because as the tire bends, these
interlocked threads wear against each other, the fabric
tire gives a shorter mileage than the cord tire. A
study of a tire section or of a piece of fabric shows
this wavy condition.

Tbe cord tire is made from thread fabric. The warp
is constructed of cords of the right number of fibres,
twisted to the proper size and woven on a loom with
relatively few filling threads of a light nature to hold
the cords together in manufacture. Usually there are
only five filling threads in two inches of cord fabric.
During frietioning, the warp threads straighten out
into approximately parallel lines, no one of which is
in contact with its adjacent partner. In the cord tire
each cord or layer of cords is separated from every
other by rubber; in the fabric tire each thread over-
laps the one adjacent to it. These are the fundamental

THE PNEUMATIC AUTOMOBILE TIRE

the more convenient demountalale rim with its straight
side tire.

In a tire, we depend not alone upon the bead but
npon fabric. There are many niceties in the construc-
tion of cotton thread and the weaving of it into both
square-woven fabric and cord fabric. Particularly
must the cloth be processed in the rubber factory in
such a way as to aUow each layer or ply to work har-
moniously under the bendings incident to service.
When a thirty-two by four inch cord tire is inflated
to sixty pounds of air pressure, there is exerted within
it an outward force of thirty tons. When loaded to
twelve hundred pounds, it is pressed in nearly three
quarters of an inch ; and every time the wheel revolves,
each part of the tire is deflected by that amount. It
is constantly bent back and forth in service. "Wire
bent this way quickly breaks ; but the fabric bends
over sis million times in each ten thousand miles.

The remarkable increase in tire service during the
last five years, is due to the scientific adjustment of
the threads that make up the fabric and cord, as well
as to the greater resistance of the rubber layers to
flexion and heat. This rubber layer called "friction
and coat" holds the plies of fabric together and at the
same time keeps them apart so that they cannot rub
against each other; it is another of the essential ele-
ments in tire construction. The fabric moves over very
small distances, yet sufficiently to develop heat. This
rubber must serve as a permanent lubricant ; not tem-
porarily, like the oil that is put in between the leaves
of springs or into the transmission or the differential
housing, for that can be changed every few hundred

131 ^^H

t also ^^H
itruc- ^^^

THE PNEUMATIC AUTOMOBILE TIBE 133

differences between cord and fabric tires. The re-
peated flexing a tire is subjected to is one of the ele-
ments of wear, indeed a major element, which cotton
resists and other materials do not.

In various parts of the tire there are several differ-
ent weaves used. The breaker fabric with its peculiar
eonstruction permits the strength and the resistance to
motion necessary to maintain the tread upon the
dosely woven body-fabric. The thinner, smaller
weaves, in lapping the bead, play a most important
part in the quality of the ultimate product ; but, in them-
selves, they are relatively simple, both in grade of
cotton fiber and method of weave.
' The tire designer must select his cotton, for the cot-
I ton fiber or staple varies greatly in length. The diam-
eter of one fiber is so small that if you were to lay two
thousand of them side by side, they would measure
one inch. Tiny and fragile as they are,
le fibers, when properly chosen with respect to
iaigth and twisted together, become, hke other com-
mnnities, strong in numbers. In a thirty by three and
one half inch cord tire there are over 1700 miles of fiber
if placed end to end ; but in a cord tire thirty-five by
five there are more than 5700 miles. The builder's
choice of fibers of the proper length gives strength
and service to the tire fabric. Yet, as is the case with
in the army, it is not necessarily the largest
Ones that we depend upon for the most work. Fibers
Vary in length up to one and three quarters inches.
How important a part is played by organization I In
the case of the tire, the fibers are organized by cotton-
mill operations into fabric and then built up by the

134 THE EEIGN OF BUBBEB

mbber maker into a tire, to the end that each ply, each
thread, and each fiber work iu unison. The manu-
factarer who is able go to control his miUions of tittle S
staples that they will act as one is the Marshal Foch ^
of tire service. When tires are run ander-inflated or
overloaded, the harmony of this organization is dis-
turbed by a sort of mass attack on one sector, which
throws too much strain on the inside plies. As a con-
sequence, breaking begins.

In tread design a cue is taken from Mother Nature,
who grows tough skin on the bottom of a dog's foot
and furthermore cushions It by pads of soft flesh.
The tread of the tire is the wearing surface, a tough
composition; but under it is a yielding foundation,
soft, flexible, and snappy.

The black tread has been evolved after a painstak-
ing, intricate study, and the chemists have worked
long and diligently in their laboratories to produce
such a highly resilient rubber mixture. When tested
on machines built for the purpose against the abrasive
action of carborundum, these treads outwear dry
leather by about two and one half times; with both ma-
terials wet, they outwear leather more than ten times.
An interesting test was run some years ago to compare
sheet-iron and several rubber compositions. This black
rubber mixture resisted the action of a powerful sai
blast three times as long as Iron. The black rubber
tread composition, therefore, on a pneumatic tire is
the material most resistant to road abrasion that the
chemist in his laboratory has been able to produce.

A tire is not a tire until it has air in it. The inner I
tube has one purpose — to hold air. Although there!

THE PNEUMATIC AITTOMOBILE TIBE 135

have been various attempts to substitute other things
than air (and far be it from me to condemn research
in this direction), thus far no substance with -which to
support the tire has been found equal to air. It is
the most easily obtained ; it is the most springy sub-
stance known ; and its only weakness is the ease with
which it escapes through a very small hole. Despite
the study of puncture-proofing and the substitution
of other substances, none of them has met with suffi-
cient popular service to call it important to the tire
industry.

The tube, made of a very extensible rubber mixture,
is the simplest part of a tire. Stretch a piece of an
old one. Notice how the part next to the tread has
deteriorated from the heat, and yet the part next to
the rim is still strong. In designing tube thicknesses
and sizes, tire designers try to choose the correct thick-
ness, length, and diameter to permit the tube to run
many miles beyond the distance that the casing will
run. A trick here lies in the design, in the compound-
ing, and in the type of vulcanization, which gives to the
tube such resistance to heat that it does not become
weakened or assume a permanently large size, a condi-
tion making it impossible to put the tube back into
another casing after the original one has been used up.

The flap of the straight-side tire is a little article
that is often overlooked. It is a piece of formed
fabric and rubber used only in straight-side tires, for
the purpose of preventing this soft rubber tube from
forcing itself down imderneath the bead. Many of the
troubles of motorists are due to the flap, which, dur-
ing the hasty application of the tire, flap, and tube

136 THE EEIGN OF EUBBER

upon the rim, is displaced, folded, or broken. The
result is that, instead of protecting the tube, the flap
becomes a means by which the tube is pinched and
quickly broken through.

The one great aim of the tire designer is to bnild a.
perfectly balanced product, so made that its parts
work in unison. After all, one of two things happens
to give an end to a tire ; either the tread wears through
or the fabric breaks under repeated bending. There
are, however, occasions when the tread wears unduly
before the fabric has really run its life, and where the
fabric breaks before the tread has been used up. The
constant aim of the tire designer is to attain this per-
fect balance; to build his tire like the "one-hoss shay."

The earlier designs of pneumatic tires followed the
principles then knoA\Ti for bicycle tires. Indeed, much
parallel invention was under way in the early nine-
ties.

The histories of bicycle and of automobile tires are
closely interwoven. Fundamental principles were
pretty generally worked out for the bicycle before the
coming of the automobile. Eeally, Daimler's first
machine was a sort of motor-cycle. Being a little
skeptical of the pneumatic, these first motor-car
builders experimented with many varieties of solid aad
cushion tires ; but as none of them was satisfactory,
they turned to the pneumatic, adopting the sLnglfr
tube bicycle tire. Although the single-tube tire was
fairly satisfactory, it would not stand up under the
heavier and faster cars. The tires were then made
much heavier and larger than they are to-day; some
manufacturers found that to keep pace with the in-

THE PNEUMATIC AUTOMOBILE TIRE 137

creasing size, weight, and speed of the automobile, it
became necessary to produce a tire built to withstand
vastly greater stresaes, Farwcll, in his "Story of the
Tire" {1912), saya: "The makers now [about 1900]
tnmed back to the original Dunlop clincher detachable
tires as more suited to their needs and began to develop
a distinct type of automobile tire. The wired-on or
Dunlop tire, which was developed into the straight-side
tire of the present day, was enlarged and strengthened
and put upon the market by its makers, the Hartford
finbber Company. At about the same time the B. F.
Goodrich Company brought out their Goodrich
clincher, which was the first American tire of this type
to be made for automobile service,

"In November, 1900, at the first exclusive Auto-
mobile Show held in the 'Gardens' there were 33 auto-
mobile makers and eight tire exhibitors, nearly all
showing single tube pneumatic and solid tires. Dur-
ing the nest two years most of the manufacturers
dropped the single-tube and were making double de-
tachable tires only." The automobile shows of then
and now appear strikingly different.

We must not pass over these early names without
giving credit to Michelin et Cie., the earliest French
rubber manufacturers, who bad the honor of first ap-
plying the pneumatic tire to the automobile. Because
the first broad use of the automobile was in France,
and the manufacturers there felt the necessity for pro-
tecting the mechanism of the car from road shocks,
this development came about.

Hard to apply and still harder to replace, these old
tires were clumsy things as a rule. They were difficult

THE EEIGN OF BUBBI2t

to inflate with any means at hai^ in those days.
They gave relatively Uttle service, and were hard to
change.

The history of the cord tire has been somewhat ob-
scared. John F. Palmer patented it for bicycles in
America in 1892- He took his patents to England,
where the new tires were so mach faster in bicycle
radng that the officials handicapped the riders who
need them. It was a gift of free advertising which
led to the prompt adoption by all riders and the ex-
tended nse of the "Palmer Tyre" made by Mr. C. H.
Gray at the India Rubber Works, Silvertown, near
London.

Mr. Thomas Sloper, however, in 1801 had conceived
the cord idea and filed a provisional specification Id
the British Patent Office. Manufacturers would not
listen to him when he sought their interest with his
germ of a great idea. So the final specification was
not filed, and the aggressive Palmer captured the Eng-
lish market.

Palmer adapted his principle to the automobile tire
in 1895 but his web tire failed. His all-warp fabric
with fine weft threads, however, was the forerunner
and basis of the thread fabric today contained in
essentially all cord tires. Sloper was employed by Mr.
C. H. Gray, who foresaw the value of the idea for auto-
mobiles and developed a successful cord tire, called the
Palmer Tyre, which was later taken to America and
made by the Diamond Rubber Co. and the B. F. Good-
rich Co., with many improvements, as the Silvertown
Cord Tire.

How ideas travel ! The cord idea began in America,

THE PNEUMATIC AUTOMOBILE TIRE 139

went to England a bicycle tire, and returned grown-
up into the automobile tire.

But the English tire contained two plies of heavy
cord, like rope. To attain simplicity of manufacture,
Americans took the lead again. The M-organ and
Wright Co. {U. S. Tire Co.) and the Goodyear Tire and
Rubber Co. almost simultaneously came forth with
tires made of woven thread fabric. It was not a suo-
. cess at first. "When the tires came to be inflated upon
a bag during cure, and the methods improved, the
nearly perfect cord tires as we know them were the
result.

Let us take a trip into the factory and see how a
tire is made. The compound for the tread, which has
been mixed in the mill-room, is delivered into another
room ; the beads are formed in still a different part of
the factory; and the side walls, which have been rolled
out on the sheeting calenders, go into still a different
room : it is a huge plant in all, turning out thirty-thou-
sand tires every day, fifteen miles of them rolling out
every twenty-four hours. The tire factory ig, to say
the least, a lively place.

A visitor finds a seeming confusion of men, machin-
ery, fabric, and rubber, with tires the outcome. It ia
not easy to picture the making of a tire, for each part
is made in a different part of the plant and assembled
at the building machine. Cord fabric is frietioned and
coated with a resilient compound on the three-roll cal-
enders of the calender room. Here the steel wipes or
frictions rubber around the threads. Ail cotton in a
tire mill is called fabric.

Since the threads of the fabric run at an angle

^^ Since t

140 THE REIGN OF RUBBER

of about forty-five degrees to the circumference of the
tire, the fabric must be cut on the bias. And so large,
heavy rolls of this rubberized fabric are conveyed
by the truck system into the bias cuttiug room, where
they are carried through rapidly operating bias cutters
that shear off certain widths. Operators roll them
up, keeping plain fabric, known as "liners," between
them, so that the adjacent layers of unvulcanized rub-
ber may not stick to itself and make the building of
the tire impossible. These bias blocks are then con-
veyed to a table where workmen overlap the edges,
using the proper width for the different sizes and dif-
ferent plies. After being thus spliced, they are rolled
up into bundles, each separated by liners, in the
proper length to make a given number of tires of a
certain size. The same cutting to width and length
of the breaker fabric is done in different places,
as is the cutting of the side-wall sheet rubber.

The tread rubber is carried to the tread-forming
room, where the rubber is softened on a warming-up
mill and squirted through the die of a tubing machine,
coming out of this die at a definite thickness and width
for each different size of tire. In some factories these
treads are formed on a calender, and in some by a
tubing machine ; but, in any event, the exact width and
thickness at each point is controlled by measurement.
The operations are conducted by skilled men, to make
certain that the exact weight, necessary not only for
economy but for quality, is gained.

Meanwhile, by an operation that would take a chap-
ter in itself to describe fully, the bead is prepared. If
it is a rubber bead, it has been formed on a tubing ma-

THE PNEUMATIC AUTOMOBILE TIRE 141

chine and pressed in a hot mold to a defined size, with
a layer of fabric around it.

At the building machine, one sees the operators fit
in the proper place a metal core. This core is de-
signed to be of the size that is correct for the inside
of the tire, depending upon the process by which it is
to be made. If it is a fabric tire, which is finally to
be finished in a mold, this core is of exactly the size;
if it is a cord tire, however, the core is a little smaller,'
for the mold operation in making a cord tire consists
of stretching it, while being vulcanized, upon an air-
or water-bag. According to the construction of the
tire, the plies of canvas are wound on this core by a
machine in the order in which they have been laid up
by those who spliced the bias strips together. The
operator places the end of the canvas roll carefully
upon the core, and sets the machine in motion. The
tackiness of the rubber makes it stick to the metal ; and
the fabric is stretched at exactly the necessary tension
as it is wound on the core. Meanwhile, rollers are
pressed by weights or springs upon the fabric in order
to join the plies to each other firmly. Half the fabric
previously having been put on the machine, the earlier
formed bead is applied on top of it, in the right posi-
tion and very accurately adjusted. Then in the build-
ing the bead is wrapped about by the body plies. Af-
ter the necessary plies have thus been built up, and the
previously formed combination of tread, breaker-fab-
ric, and cushion have been laid on and rolled down
under pressure, the tire is taken to what is known as
a finishing stand. Here the side walls are applied
and the tire inspected.

142 THE REIGN OF RUBBER

To gain accuracy and speed, mach nice inventive
work has been done in the making of tire-building ma-
chinery. Machine-built tires are more precise and
uniform than those built by hand. Before the tire
is modeled to its approximate shape and ready for the
final step of molding, there are a number of operations
to be performed by these machines. If it be a fabric
tire, the operators who work on the finishing stand lift
it to a rack on a truck. If it be a cord tire, on the other
hand, it is sent to a stripping table, where the core is
removed, the tire is dusted on the inside, and an air-bag
or a water-bag of heavy, thick rubber, which has been
previously painted with soapstone solution to prevent
it from curing to the fabric, is inserted.

If it be a fabric tire, it then must go down to the vul-
canizing room, where there are long rows of heaters.
The tire is trucked to these heaters; and a mold, in two
halves, is brought by a powerful conveyor, in front
of the workmen, who lift the tire and its core
and place it in the lower half of this mold. The
mold has been designed so that it is of exactly the
exterior shape that the tire is to have when finished,
including all the lettering and other features. As the
tire travels along a metal belt, the top half of the
mold comes down from an automatic conveyor that has
carried it out of the way above the operators, and is
carefully guided into place on the tire. The mold
gaps open, for the tire in this form does not fit it ex-
actly. In the mold are the protuberances that form
the depressions in the tread design and hold the tire
away from the mold until pressure forces it into place.

Carried away on the automatic conveyor, the tire.

THE PNEUMATIC AUTOMOBILE TIRE 143

together with many others, is loaded into the shell of
the vulcanizer, in the bottom of which is a plate or
platen, which, before the mold was filled, rested in a
position nearly at the top of the heater. This platen
is fixed upon a plunger moved by water pressure in a
cylinder below. The lowering is done by simply push-
ing the molds down a short inclined plane upon the
platen, until there has been made a stack of twenty to
twenty-five molds in the heater. After this, the cover
is placed on this open vulcanizer; by a simple device
it is locked in place so that no steam can escape. The
molds are then forced together by hydraulic pressure
and the soft rubber takes the form of the mold, after
which process steam is applied and the vulcanization is
begun.

Great accuracy has been gained in recent years from
the use of automatic, temperature-controlling instru-
ments by which an operator has to turn but one valve
to maintain an exact temperature during the desired
time. At the end of the time, it automatically turns
the heat off and gives a signal by which the operators
know that the vulcanizer is ready to be discharged.
In the discharge the hydraulic ram raises the molds
to a height where the men can pull them by a rope and
a winch upon the traveling conveyor, along which they
are carried. The two halves of each mold are separ-
ated, the tire removed, and the mold again filled.
These are to the production man beautiful operations
that give rapidity and accuracy to the vulcanization of
tires.

In the case of a cord tire, a somewhat different proc-
ess is used; for, as stated, an air- or water-bag is

THE PNEUMATIC AUTOMOBILE TIRE

drel. Once, however, upon the mandrel, whether
sheeted or extruded, it is wrapped with fabric.

After this operation, it is stacked on trucks, the
units being separated by iron plates at the end; and
the truck-load of mandrels with their rubber tubes
upon them are pushed into long horizontal vuleanizers,
the doors closed, and steam turned in. Sometimes the
valve-pad reinforcement, which is a combination of
mbber and fabric cut to an oval shape, is applied be-
fore vulcanizing; at others it is applied after vulcaniz-
ing. At the end of the time of vulcanization, the tubes
are stripped from the mandrel by the simple process
of blowing air between the tube and the mandrel.
Taken to another room the tubes have, by a skilfully
used bit of apparatus, the two ends buffed, cemented,
and vulcanized together. From here, the tubes are
sent to a table where the valve stem is applied, if it
has not been applied, as in some plants, before the
splicing operation. They are then inspected in water
for leaks, and packed for shipment.

How should we take care of a tiref The principle
developed in the field of engineering of only loading
a beam to within a reasonable factor of safety applies
here. If you build a house, you make certain that the
Ijeams underneath your floor are large enough to carry
■nany times the greatest load that you ever expect to
assemble upon that floor. Look at the picture of a
fire section under no load, normal load, and overload.
The inside of the tire has become flattened with over-
load or nnder-inflation, conditions really affecting the
tire in the same way; and the inside layers or plies,
slightly shorter than the outside layers from bead to

I
I

THE BEIGN OF RUBBER

bead, then carry too great a proportion of the load.
As a result, when that tire is driven over a stone, it
is liable to take a shape that seriously distorts it
And, too, because of greater internal friction, the
amount of heat is increased. Hence, the fabric weak-
ens, the rubber deteriorates rapidly, and the little
fibers one by one begin to break ; until some day, when
least expected, one of the plies will break through
Then, instead of a six- or eight-ply tire, there will be
only five or sis. As in the case of a rope with one
strand broken, the load becomes excessive for the other
strands; and some time thereafter they will break
down with the usual blow-out. A tire is really a sus-
pension-bridge, the cords being fixed at the two beads
and shaped by air pressure. The air ie not much com-
pressed during service, but it is required in order to
maintain the cords under the necessary tension and to
permit them to work in the most natural way.

Of the total power of the motor in an automobile,
part is absorbed in the mechanism of the car and the
remainder, estimated to be more than 80 per cent., is
transmitted to the rear tires to be expended in push-
ing the machine against the wind, up liiU, and against
other resistances. Driving over bricks and bumps,
dodging around automobiles at the side of the road,
our tires are subjected to power as well as dead load
and to sudden changes in strain. These jerks, bumpa,
and cuts by rough stones on the road 's edge, that let
water into the fabric, are the killing forces that de-
stroy tires. If tires were treated as most of our prop-
erty is, we should carefully examine them month by

THE PNEUMATIC AUTOMOBILE TIRE 147

month. The older ones should be shifted from the
position of greatest work, namely, the rear, to the
front; for we should think of them as old faithful
horses gradually to be retired to easier jobs, while the
younger ones are called upon to carry the heaviest
bnrdfns.

How much work does a tire doT If one thirty-two
by four inch tire on the rear wheel of a car carrying
a load of fifteen hundred pounds runs ten thoueand
mileB up a 4.4 per cent, grade, the work it has to do,
engineers tell us, is 2026 horse-power hours. This is
equivalent to lifting more than four billion pounds of
Btone up one foot. The computation, to be sure, as-
smneB the tire to be on the up-grade all the way ; but
if it goes up-grade only one quarter of the time, the
ffork done would lift the Washington Monument about
twelve feet. When your tire goes one hundred miles,
it does as much work as you would do if you shoveled
320 tons of coal into your second-story window. Dur-
ing such a job you would perspire pretty freely; the
tire heats, too. We have learned by experiment that
when this four -inch tire was run for an hour at twenty
iniles per hour, the temperature of the tire just under
the tread had increased 37^^ degrees; at forty miles
an hour, the increase was 75 degrees. In the hot days
with the thermometer ninety -five degrees in the shade,
and 110 degrees on the road surface, imagine the tire
heated to 180 degrees, or nearly enough to boil water.
U it any wonder that the rubber wears rapidly then?
These figures of temperature show that the motorist
has considerable to fear if he rides at excessive speed

148 THE BEIGN OF BXTBBEB

in hot weather, or if he permits his air inflation to be
reduced to the point where there is maxiTnnTn flexing
and consequently increased rise in temperature. Be-
gardless of that, rubber tires resist just such wear to
a greater degree than any other known structure.

Motoring is not whoUy a matter of engines and
chassis. ** Bone-shaker'' vehicles are gone forever.
To the pneumatic tire may be given credit for the as-
tounding growth of the automobile, for it has per*
mitted both speed and comfort.

CHAPTER X

TRANSPORTATION BY TRUCK

Transportation is a mighty word. Indeed, civili-
zation measures its scope and development by its eflS-
ciency in moving men and materials. The change from
the days when each household was self-sustaining and
all life was agricultural is a history of transportation.
The Neanderthal man killed his meat in the forest and
carried it to his cave. He lived from day to day. The
barter principle of trade was given up only as trans-
portation made possible the movement of commodities
from distant fields of origin to centers of use. Banks,
warehouses, and exchange systems depend upon move-
ments of goods over the world's highways.

After human effort came the ox-team, after that the
horse-drawn wagon, then the railroad, and finally the
improved highway for motor transportation. In fact,
if one looks over the world as it is now, he finds each
of these ancient and modern methods of movement
realized in different parts of it. The measure of the
intelligence of peoples, in any event the standard by
which they are rated in the family of nations, is pretty
largely that of the eflSciency of their transportation
systems. The famines in China illustrate how vital
highways are in modern life ; for there were provinces
filled with starving people, and but a few short miles

149

150 THE KEIGN OP EUBBER

away, as we in the United States measure distance,
there was plenty of food; yet the lack of highways
made it impossible to move the food to those who
needed it most.

Our great railways are main lines of travel, requiring
secondary lines with fast and prompt service to feed
them with the products of the soil and industry. For
this purpose the motor-truck, developed during the
last two decades, constitutes at once the most spectacu-
lar and efficient means. The tourist does not enjoy
the crowded thoroughfare; his horn too often fails to
stir the truck driver ahead to yield half of the pave-
ment. Yet the very freight the truck carries means the
prosperity that makes touring possible.

The motor-truck takes its value from certain charac-
teristics that may be termed fundamental. It can move
goods at relatively high speed ; its power is sufficient
to permit its carrying loads of any size to meet the de-
mands of industrial and commercial enterprise. It is
adaptable, more so than any other known vehicle, to
various service requirements. The milk-truck in early
dawn rushes its supply from the farm dairies to the
centers from which babies are fed ; dirt from excava-
tions for sky-scrapers is hauled away in dump-trucks;
the department-store delivers its merchandise for miles
into the country. Through the efficiency of the truck,
regularity of service is habitual, although still the con-
dition of roads affects seriously the movement and
life of the vehicles. There is, to be sure, some differ-
ence of opinion among students of motor transporta-
tion as to how far the range of trucking may be con-
sidered efficient. The railroad, however, is the main

TRANSPORTATION BY TRUCK

line and the motor-truck the feeder, or the rapid means
of commnnication between adjacent industries or cities.
Motor transportation is economical, for the cost per
ton mile has been reduced to a point making the ex-
tension and use of trucks possible. Probably the
truck will never be able to compete with the railroad
OD long hauls.

Recent years have witnessed a striking change and
development in the use of the truck, for it has come
to be a serious competitor of the trolley-car. Both the
bus and the street-car have their definite places; each
has its advantages, I would not wish to say that
either will displace the other. The motor omnibus
systems in New York, London, and Paris as well
enough known to support a conception that they would
not be conducted upon so extended a scale were not the
coat of transportation low and the profits unmistak-
able. Freedom of movement; ability to follow the
lines of growth of the community and so give service
where the lajang of tracks for trolley-cars would be
highly expensive ; avoiding obstacles, as in the case of
parades, fires, or temporary obstructions — this funda-
mental principle of flexibility, without doubt, renders
the motor-bus a means of passenger transportation
that has come to stay and that will develop in the fu-
ture. Recently some busses have been run on rails,
but they are still in an experimental form. There is
no one of these different types of motor-trucks, busses,
or cars in which rubber or the rubber tire in one form
or another is not an essential. Indeed, a feature of
the latest addition to this family is the cushion driving
wheel of the rail car, in which, underneath the usual

152

THE REIGN OF BUBBEK

steel wheel and protected from the weather by side
flanges, is a special rubber cushion to give comfort to
the rider. The rubber tire, therefore, is a commoditj
without which it is doubtful if any of these transpor-
tation schemes would serve.

From the time when Sir Isaac Newton, in 1680, sug-
gested the steam-driven wagon, down through the
years, attempts have been made to revolutionize trans-
portation by self-propelled vehicles. The early disap-
pointments and failures of the steam wagon in ita
various forms were due to the lack of a soft cushion to
smooth out road inequalities and to reduce vibration.
Probably for this reason more than any other, these
early rapid-transit enthusiasts came to the invention
of the solid road-bed and the smooth rails that we as-
sociate with the railroad. The first plan to avoid
shocks was to cushion the wheels with tires of sohd
rubber. The idea of air in a tire was a later develop-
ment. The electric vehicle pioneered by Colonel A. L.
Riker in 1898 was one of the earliest truck develop-
ments, although the steam truck was more fully worked
out in England and the gasolene internal combustion
engine was developed in France and America. One
still sees on the English streets steam-driven trucks.
For all of these heavy services the solid motor tire,
which was a natural offshoot of the solid carriage tire,
has proved to be the most logical medium by which
cushioning, long life, and efficiency can be gained. The
solid tire differs from the pneumatic tire, which is 80
vital to passenger-car transportation, in being rubber
all the way through.

The inventor of the original solid rubber tire is un-

TEANSPORTATION BY TRUCK 153

known. The history of tires in England seems to give
credit to Thomas Hancock who, in his book written in
1856, suggests solid rubber tires to relieve vibration.
They were, however, manufactured before 1856, for
the records show the firm of Charles Mackintosh &
Co., to have manufactured such tires for vehicles as
early as 1846. Hancock says: ^^ These tires are
about an inch and a half wide and one and a quarter
thick. Wheels shod with them make no noise and they
greatly relieve concussion of pavements and rough
roads; they have lately been patronized by Her
Majesty.'* But because of their sticky qualities and
the property of softening readily with heat, these early
tires gave a relatively short service. There is a
patent on record in England, granted to Thomas Smith
in 1845, the principle of which was spokes set within a
felloe of metal in a trough-like form, the open part be-
ing outward and containing a tire. No mention, how-
ever, is made of rubber in connection with this patent.
During 1856, in England, M. Coles Fuller brought out
a combination solid tire composed of cloth, canvas, or
other fibrous materials.

The first introduction of solid tires for cabs in Lon-
don was in 1861, but difficulties were experienced in
attaching the rubber to the wheels. In 1863 N. H.
Oarmont took out a patent for holding the metal part
of the tires on the felloe with a dovetailed section to
receive the rubber tires, which were grooved to fit the
channel. Later, another company, known as the Noise-
less Tyre Co., was formed to furnish tires for the
Shrewsbury Cab Co., the first firm to introduce the use
of solid rubber tires in England. Upon the invention

THE EEIGN OF RUBBER

of the bicycle in England in 1867, it was found neces-
sary to relieve the vibrations of the old ' ' bone-
shaker"; and solid rubber tires were manufactured
that were cemented into a groove in the rim of the
machine. These tires were followed in 1879 by cushion
tires, which, althongh no larger in diameter, possessed
increased resiliency produced by a small hole running
through the center. They were specially devised for
what was then known as the "safety" machine, which
followed the old high bicycle.

The introduction of the motor-bus in England ne-
cessitated a further departure with regard to rubber
tires. Not only were pneumatic tires out of the ques-
tion, but it was found impossible to retain solid rub-
ber in the rim when the weight of some six or seven
tons was imposed upon it. Therefore, it was necessary
to vulcanize some sort of a retaining band in the bed
of the rubber. Now, it is a very difficult matter to
unite thoroughly a non-yielding body like steel with an
elastic body of the nature of rubber. In time, this
has been effected. So metal rings of various sections
were used for this purpose, and detachable rims en-
abled these ring sections to be fitted on the felloe of
the wheel. But the Scotland Yard authorities pro-
hibited the use of sectional tires for use on public
vehicles in England; and this action, to some ex-
tent, checked the development of this class of tire.

The Shrewsbury & Talbot tire, the trade name of the
Carmont tire, was introduced into New York. It at
once gained approval, and it remained until later de-
velopment drove it from the market. It is interesting
how the point of view of the public has changed in the

TRANSPORTATION BY TRUCK

155

last fifty years, for the early solid tire offered the
pcfalic in 1856 by the Boston Belting Co., was received
with the unfailing skepticism then ready for anything
in the nature of an innovation. Because rubber wheels
made no noise, they were considered detrimental to
tie safety of pedestrians ; and the inventors were de-
terred from taking out patents by the authorities, who
warned the manufacturers that vehicles equipped with
such tires were a menace to public safety. We even
find the rubber sole and the rubber heel catalogued
under the name of "sneakers," even though the safety
and comfort of the user, as well as economy, are in-
creased by their use.

The most practical development of the solid tire for
carriage purposes was one invented by Arthur W.
Grant, later known as the Kelly-Springfield tire,
which probably more than any other one invention led
to the popularity of rubber on horse-drawn vehicles.
The rubber was held in place on the wheel by means
of longitudinal wires running through the tire and
forming circles of smaller circumference than the rim
flanges. Built of long-lived ruhber mixtures, this tire
was capable of positive attachment in the channel or
rim. A little later the tire was modified by tlie so-
called "side-wire" carriage tire, invented by James
A. Swinehart of Akron, in which the wires were passed
outside the imbber body.

The automobile has so completely dominated the
field that the horse-drawn vehicle has become only a
means of wagon transportation, and the internal wire
or any other type of carriage tire has essentially dis-
appeared. We need not, therefore, describe the nn-

156 THE EEIGN OF SUBBEE

merons other methods of holding a piece of solid vnl-
canized rubber on a wheel for carriage purposes.

After years of development and trial, the solid truck
tire of to-day has come down to us in one form : a steel
base upon which is a layer of hard rubber, and, upon
that, the mass of soft rubber giving comfort, cushion-
ing, and resistance to wear. The fiinction of the mo-
tor-truck tire is to provide traction for the wheels,
and, as a protection to the mechanism of the truck and
load upon it, to cushion them. The first idea of the
metal-hase tire came from Europe— a steel band
grooved in the form of dovetails. Into these grooves
was forced a layer of rubber mixture that would be-
come hard rubber on vulcanization. This served as a
stiff base impossible to remove from the steel, although
chemically not united with it. Before vulcanization
of the hard rubber, a layer of a resilient tread com-
position was applied, and the whole vulcanized in a
mold under pressure, so as to form the shape desired
Thus was developed the wireless tire introduced into
the market in 1909. To-day the steel-base tire is uni-
versally used on motor-trucks and is called the truck
tire.

The steel base on which this solid truck tire is built
is a continuous band of channel-steel, the lower surface
of which is smooth and the surface between the flanges
machined with a series of circumferential slots that in
cross-section have the appearance of dovetailed de-
pressions. Because accuracy of measurement is im-
portant, that they fit the wheels, the manufacture of
these bases is a specialized process in steel mills.
They must also be made to fit exactly into the metal

TEANSPOETATION BY TRUCK 157

molds after the tire is on them, during the vulcaniza-
tion process. In the course of manufacture, the sur-
face of the steel is roughened* by numerous corruga-
tions. In some factories fine, sharp, flint-sand is
blown against the base with a powerful air-blast; in
others, it is copperplated ; in others, it is treated with
acid to pit the surface with an infinite number of fine
depressions. The purpose of this work is to give a
surface to which the hard rubber mixture may hold in
innumerable little points of attachment, these points
making the security of the hard rubber base certain.

In the operation of manufacture in the rubber mill,
after the metal base is thus cleaned, in order to fill
these little depressions with a hard rubber composi-
tion, it is coated with cement. After drying, this base
or permanent band is mounted upon a horizontal shaft
placed in front of a special calender. The hard rub-
ber compound containing an amount of sulphur ap-
proximating 32 per cent, by weight of the crude rub-
ber has previously been mixed in the mixing room.
The numerous other ingredients are chiefly those ma-
terials that serve to vulcanize it simultaneously with
the wearing part. This hard rubber compound is
softened and passed through the rolls of the calender,
which form a sheet of unvulcanized hard rubber mix-
ture, the precise width of that part of the base be-
tween the flanges. When the proper amount adheres
to this steel band, the base, with its layer of unvul-
canized hard rubber, is taken to another calender,
where a continuous sheet of a soft rubber mixture is
run, until the right thickness, depending upon the size
of the tire, is rolled up upon it. At this point, the cal-

THE REIGN OF BUBBEB

E operation is stopped, and the tire U removefJ
fram the support of the wheeL Beetangular in section,
it then is taken to the trimming machine, where the
excess of soft mbber is resnored. By this process the
shape in section of the tire is made as nearly as poB-
aiUe to confonn to the shape desired after vulcani-
zation.

The soft or wearing rubber may be applied to the
hard mbber base by another process. First it is
softened upon a wanning-up milL After softening
it the workmen feed it into the opening in a heavy
talnng machine, where it is forced by great pressure
throagh a die. From the die the mbber issues as a
long, solid mass. The die is the shape in section that
the finished tire is expected to be. Different sized
tires — fonr-ineh, five-inch, six-inch, seven-inch, etc,—
require dies corresponding approximately to the size
desired. The mass of rubber is forced throagh this die
until a strip a little longer than the eircumfer-
ence of the tire has been passed out of the machine. It
is then cut off and laid away to cool. Finally, when
ready for building up on the hard rubber base that has
been run on the calender, this mass of soft rubber is
roughened on the surface where it will be in contact
with the hard rubber. After being carefully cemented
with a rubber cement and dried, it is placed in what is
known as Bu np-setting machine capable of handling
accurately and easily as much as 150 to 300 pounds.
This long mass of robber is there applied carefully to
the hard rubber ; and after preliminary pressing and
the fitting together of the two ends, it is in the ap-
proximate form in which it will issue from the mold.

T TR

"l By either of

TRANSPORTATION BY TRUCK

159

By either of these two processes, the calendering proc-
ess or tnbing-machine process, we have a steel base
with a hard rubber layer upon it, and upon that the
masB of soft rubber of the size and form of the final
track tire-

This tire is then taken to the vulcanizing or curing
room, ready for the final operation of vulcanizing.
The vulcanizing process is similar in principle to that
used with a pneumatic tire; that is, the doughnuts,
with their tires in them, are placed upon a movable
plate or platen held at the top of a hollow, cylindrical
shell known as the "heater" or "vulcanizer." By
mechanical devices the molds are pushed on top of the
plate, the plate is lowered by letting out a little water
through the hydraulic mechanism, and another mold
IB placed on top of the first. The tires then are
pressed by hydraulic pressure into the exact shape
and conformation of the inside of the moulds. When
the steam is turned into the vulcanizer around the
molds, the vulcanizing operation begins.

There is probably no part of rubber operation that
requires greater care in manufacture than this one of
mlcanizing or curing a solid tire. Not only are we
dealing here with rubber that is to be vulcanized, but
with a thick mass of rubber. The thermal conductivity
of rubber is very low; in other words, it is a very
good heat-insulating material. Furthermore, various
compounds are different in their resistance to the pas-
sage of heat through them. It requires from one to
Iwo hours to bring the temperature of the center of
an ordinary-sized solid tire up to that of vulcanization.
For this reason, solid-tire curing temperatures have

THE KEIGN OF RUBBER

usually been kept relatively low and the time of vul-
canization relatively long.

After the vulcanization is completed, cold water in
some plants is run into the heater and allowed to re-
main long enough to cool the mass of metal and rubber.
The control of steam has been maintained by auto-
matic temperature-controlling apparatus, the ma-
terials have been carefully examined, and every pos-
sible precaution necessary to insure uniformity of one
of the most delicate products made has been taken — a
ppoduct that is submitted to tremendous variations in
service. After the tire comes from the mould, it is iu-
the little extra amount of rubber that has
flowed out of the mold and which is known as rind, or
overflow, is cut off, and the tire is ready for sale.

The solid tire of the permanent-band type is tbea
ready to be applied to the wheel, and much of its serv-
ice depends upon proper application. To apply the
tire, the wheel is removed from the truck and laid upon
a heavy press operated by hydraulic power. The tire,
which fits the felloe band of the wheel tightly, is placed
in position ; then the two plates are brought together,
the action forcing the band or base of the tire upon the
wheel. The process usually requires a pressure of
twenty tons — in any event, far more pressure than any
tire will ever be subjected to in service.

There have been several types of demountable tires
made which are capable of application in a garage or
on the road; but they are gradually disappearing be-
cause they work loose. Since the tire itself is so heavy,
one or two men can scarcely apply it while the wheel is
still on the truck. Therefore, the permanent band-

TBANSPOETATION BY TRUCK 161

pressed-on type has come to be the most largely used
truck tire.

We see some wheels equipped with two tires in the
rear; these tires or ** duals" have a wide use because
two tires radiate the heat more readily than one.
Since there is not so heavy a mass of rubber to ab-
sorb the heat, there is consequently not so much dif-
ficulty of radiation. And there seems to be a somewhat
greater gasolene efficiency from the truck when there
is a relatively small amount of rubber in actual con-
tact with the road. Skidding, too, is reduced by the
dual tire ; and since the units are relatively small, it is
possible for a fleet of trucks to carry the same size of
tires in front and in rear, using them singly on the
front wheels and in pairs on the rear ones. The large
single tire, however, has its field; and it would be
scarcely wise to say that any one type of tire, single,
dual, or any other, has an unlimited field of usefulness.

The solid tire is probably subject to more abuse
than any other rubber article, loaded as it often is to
double the amount the tests have proved advisable.
Run at speeds by which a high degree of heat is gen-
erated, the mass of rubber being unable to radiate its
heat so easily as a pneumatic tire, truck tires have
been known to absorb heat until the temperature in-
side them has become so great that the rubber decom-
posed with a generation of gases, and the tires blew
out. In all the data that have been gained about
blow-outs it is a safe statement that they rarely occur
3xcept when the overload of the truck is so high that
it is beyond the ability of tires to stand it. This
raises one of the vital questions for the truck user;

THE REIGN OF RUBBER

namely, the relation of size of tire to the load he ex-
pects to carry. Despite all arguments to the contrary,
it is economy for him in the long run, whether he uses
one make of tire or another, to pnt on his truck that
tire proportioned in size to the loads that he wishes
to carry, to the speed the truck will stand or the law
allows, and to the road conditions. By so doing, he
will gain a service before the tire is broken down that
will make additional cost for the larger tire an econ-
omy rather than an expense.

Non-skid devices on solid tires, such as chains, cause
some trouble, and there is a certain amount of confu-
sion among users about them. While on the pneumatic
tire the chain is capable of movement, on the solid tiro
there usually is but one place where it sets itself
against the rubber. Proved from the days of the in-
ternal wire, it is true that wherever rubber comes in
contact with an inflexible body, such as metal, it will
wear out rapidly. Thus the chain wears out the solid
tire at its points of contact. This has led the manu-
facturers to develop non-skid tires, which have served
to hinder slipping upon wet pavement, snow, or ice.
There is still a great field, however, for improvement
in devices which will resist the slipping tendency and
yet in no way injure the product.

Many trucks are equipped with large pneumatic eord
tires, some of them as much as nine inches in sec-
tional diameter. These extra large ones have found
their way into extended practical use, although the six-
inch, seven-inch, and eight-inch tires are the usual
sizes. The fundamental advantages resulting from
the use of pneumatic tires on trucks are cushioning and

TEANSPORTATION BY TRUCK 163

traction greater than can be obtained from the solid
tire. The cnshioning ability of a pneumatic tire,
when not inflated too highly, is about four times that
of a solid tire of the same carrying capacity. As a
result, the operation of the truck is faster, with con-
sequent economy of operation; there is less injury
to a fragile load, for the riding is easier; but there is
grave danger from blow-outs and punctures. Gen-
erally, pneumatic tires have been used only on the
smaller trucks, namely, those up to three tons in carry-
ing capacity; for the four and five-ton trucks the
Bolid tire still leads.

Technical men still discuss the practicability of pneu-
matic tires ,on trucks. There are delays caused by the
changing of tires even when demountable rims are
used. Since the rim and the tire are heavy, and the
rim is generally rusted on, the time required to make
a change is often a serious matter. Furthermore, the
air pressure carried, from ninety pounds in a six-
inch size up to 130 pounds in the nine-inch size, is
much higher than for the smaller tires. Most garages
are not equipped with pumps capable of maintaining
these higher pressures. And, too, the center of grav-
ity of the trucks is raised, for the pneumatic tire is
higher than the solid tire. This has led to a few ac-
cidents when blow-outs have occurred and trucks have
toppled over on the road. As a rule though, such dif-
ficulties have not been numerous; and the pneumatic
tire on trucks is probably here to stay. Such beauti-
ful products are these big pneumatic tires that it is
always a pity when a puncture does occur, to see them
ruined before the truck can be stopped.

164 THE REIGN OF RUBBER

Although some wonderful long-distance hauling from
the rubber metropolis, Akron, to Boston and to San
Francisco has been done on trucks equipped with pnea-
matic tires, experience differs. Many seem to believe
that the pneumatic tire spares the trucks numerons
jars and strains ; and, therefore, the truck itself can be
made lighter. But, and this is important, if the truclt
be spared jars, it is because of the air-cushion. Be-
cause these cord tires contain eight to sixteen plies
of cord fabric, they are stiff. To attain long life for
them enough air pressure must be used to avoid too
much flexing with consequent cord breaking. The
compressibility and elasticity of air enables the tire
to absorb jars; therefore, when air pressure is high,
the tire is hard — indeed, more so than a solid tire.
Then the purpose is defeated. Highway engineers
realize that when the pneumatic tire is inflated as it
should be, the pressure to the square inch of road con-
tact is the same regardless of the load carried, and is
based entirely on the necessary inflation pressure. If
in obtaining wider area of contact the inflation pres-
sure is reduced, the tire will become unduly flattened—
a condition which will lead to rapid deterioration. To
balance low air pressure for softness against high
pressure for mileage is not possible in large pneu-
matic tires.

The solid tire, being made completely of rubber,
bulges out under load, because it cannot be compressed,
bnt it is sufficiently plastic to flow. If you place a pen-
cil with the soft eraser upright on the desk and push
it downward, the eraser will bulge at the sides; it is not
compressed but is displaced. A rubber tire oozes out

TRANSPORTATION BY TRUCK 165

in the same way ; and as it spreads on the pavement,
this so-called traction wave flows aroand continually
through various sections of the tire and causes in-
ternal action. The designers, however, have so ar-
ranged the shape of the tire that even if it does flow,
only internal heat results, which, if the tire is used
properly with respect to the load carried, does not be-
come sufficiently excessive to have a serious effect upon
its life. Since there is no danger from punctures,
cuts, and so on, the average mileage of the solid tire
is greater than that of the pneumatic tire.

Of recent years, a new idea has been expressed in
the building of tires that combine the softness of the
pneumatic under low inflation and the length of life
of the solid. Resilient solid tires capable of service
under heavy trucks will solve the truck tire problem;
for these permit speed, ease of riding, freedom from
changes on the road, and longer mileage than is pos-
sible from the large pneumatic. This type is the
track tire of the future.

In truck transportation heavy loads are demanded.
Can the roads stand the pressure? A road is, after
all, nothing more or less than a hard layer of material,
brick, concrete, macadam, upon native soil. If this
layer is made thick enough, heavy loads may be car-
ried over it without danger of breaking through. But
when, as has been (be case in too many instances, the
highway engineers have simply floated a thin layer of
brick and concrete upon clay without drainage to re-
move water, the trucks have actually broken through.
Increased speed of a vehicle tremendously increases
the impact that its wheels make on the roadway where

166 THE REIGN OF KUBBER

there is any unevenness. However, the answer to the
maintenance of roada probably lies less in a limita-
tion either of the type of tire or of the width of contact
with the road than in road construction. Roads should
be heavy enough to carry the future motor transport.

Since motor transportation on highways is here to
stay, would it not be wise to build roads of a width
to carry two streams of traffic with safety; of a con-
struction sufficiently deep to carry increased tonnages
at low cost per ton-mile; with a drainage system to
carry off the water t Roads should permit perma-
nence and flexibility to the development of motor
transportation. Even as they are, streams of trucks
carry goods and people over hundreds of routes.

Statistics may be dry, but they stimulate the imag-
ination. In the economies of truck use, railroad men
recognize the advantage of the motor-truck in short
branch-line operation, trap-car service, suburban dis-
tribution, terminal distribution, and the utilization of
outlying yards in lieu of yards in congested districts.
In the handling of food supplies from farm to city the
radius has been extended by about fifty mUes, a matter
of vital moment for milk and other perishables, which
serves to save time for the farmer and to reduce thfe
cost of living. Education is affected. Consolidated
schools in country communities, with the improve-
ments thereby obvious, have been made possible
through the speed and safety of the motor-bus for the
transportation of children. This use is rapidly grow-
ing.

The extent to which motor-truck haulage has pro-
gressed is well set forth in a census by the United

TRANSPORTATION BY TRUCK

States Bureau of Public Roads for the eastbormd traffic
only on the Boston Post Road at the New York-Cou-
necticat line in October, 1921, which shows nearly every
type of commodity and many million tons being
carried. For such transportation the total number of
public express lines is probably about one thousand,
Bays the National Automobile Chamber of Commerce ;
and a Senate committee has estimated the annual
motor-truck tonnage hauled in the United States over
the highways at 1,438,000,000 tons. In the motor-bus
field 108 cities were using motor-bus lines at the begin-
ning of 1922.

But truck tires contribute to the esthetic as well as
the economic welfare of a nation. In England, the
char-a-banc is changing the life of its people. No
longer are the delightful, picturesque little places in-
accessible. The railroad is never a good tourist route.
The highways, hedge-lined, are beautiful. A trip
from London between the rows of brilliant rhododen-
drons down to Salisbury, the winding road along
Runnymede, leaves memories never to be forgotten.
Where the automobile has shown these beauties of
England to hundreds, the char-a banc carries thou-
sands. The English people are discovering England,
and they are doing it on truck tires.

THE REIGN OP RUBBER

They took precedence as follows : Hay~ward, Ford {or
M«ypr), New Brunswick, Newark, Candee, Naugatud,
Botiton Rubber Shoe Company, Providence (or Na-
tional). We had three styles of boots, the 'Hip,' the
*Knco' or 'Cavalry' and the 'Short.' Shoes were
Mimply 'overs,' 'buskins,' 'three-strap sandala,' 'one
strnp iDCiiidals, ' and 'Jessie sandals.' The arctic was
jnHt come into use at the Naugatuck Company under
tho Wales patent, which was however not sustained,
and every one went into the making of arctics."

Thns has developed over the years one of the most
intricfite phases of the entire rubber industry; for if
one looks to-day into the catalogues of the many large
intitilntions that make rubber boots and shoes, he finds
them classed something like this: There are "boots,"
viz., as we know them, boots that come to the knee or
to the hip, loved by the small boy in the spring; there
are the "miners," a water-proof boot particularly
employed because of the heavy work on ore or stone
that it must resist; there are the "dull shoes," the
"lumbermen's," usually a leather or a woolen top
shoe coming nearly to the knee, with only the bottom
|.»art around the foot made of robber; there are the
"nrlios" and the "gaiters": and finally there is that
miftcollHneoas group classified as "light goods."

In lutler to give some idea of the extent of these
Htj')e« Mid sises, the eaUlognes have been analyzed
uf four iMkiling nibber manafaetnrers, viz., the B. F.
OotHtri<4t IV «t Akron. Ohio: the Mishawaka Woolen
IV Hi MlK^WAka. Indimna: the Hood Rubber Co. at
WalwtowUi »Us*»chus*tts: aod the United States
HuhWr i\v in «v*r»l differeat factories. The analy-

FOOTWEAE AND CLOTHING 171

Bis shows that the styles and sizes made by these four
companies when added together give a table that is
aBtonishing in its intricacy :

dassification

Number of Styles

Boots

7,953

Miners

850

Dnll Shoes

4,616

Lumbermen

6,027

Arctics

7,953

Oaiters

8,358

light Goods

41,930

Total

77,687

Thus there are 77,687 varieties of shoes and boots
of all kinds made by four companies alone. Each of
Qiese styles and sizes is here computed as a pair, and
consequently the number of individual shoes, each dif-
ferent, reaches the astonishing total 155,374. These
figures give some idea of the tremendous intricacy
involved ; the problem of manufacturing, warehousing,
inventory, etc., is so vast that out of the total rubber
industry in all its phases it is probable that the boot
and shoe end of it is the most complicated. Figures
for 1919 show there were 9,208,000 pairs of rubber
boots made, and 66,195,000 pairs of rubber shoes and
overshoes, or a total of 75,403,000 pairs. These had a
sralue of $90,780,000.

Light shoes, as we call them in the rubber industry,
ire generally known as rubbers; they are the light-
veight rubber overshoe that we put on to protect
vater-absorbing leather shoes on a rainy day. When

THE BEIGN OF RUBBER

baying rubbers, a customer of the older generation
usually had laid before him by the clerk a pair pulled
out of a drawer containing a heterogeneous assort-
ment, each two tied together with red string. A rub-
ber shoe was stretched over the leather shoe; there
waa no question of fit.

As this clumsy, ill-fitting shoe, formerly known as
the "gum shoe," often peddled about the country in
market baskets, has been replaced by its stylish mod-
em successor, wrapped in tissue-paper and packed in
a neatly labeled carton reposing on the shelf of the
dealer with all the dignity of a leather shoe, there has
come a significant change in the rubber shoe industry.
Now it is necessary to use craftsmanship; and the
rubber shoe last designer, who determines styles,
is an important factor. While he is little heard of,
he affects the appearance of the feet of the nation
about as Paris atfects the appearance of women's
dresses. Since styles of leather^shoes are so numer-
oua, the rubber designer must gather his ideas from
the leather shoe trade, attending the style shows, de-
termining what the leather shoe changes are going to
be, and adapting his rubber shoe accordingly. He
tries to fit as many different styles of leather shoes
aa possible.

The first step the designer takes is planning tie
last. A last is nothing but a wooden form, Bome-
times an aluminum one, of the size and shape for the
particular style and size that is to he made. There
are the high heels of the Louis type, the medium or
Cuban heel, the low heel, the long vamp, the short
vamp, the high instep, and the low instep. After he

FOOTWEAR AND CLOTHING 173

has grouped all these styles together, he selects those
which possess the most points in common. The shoe
of each groiip most closely typical of the lot is then
worked up in wood into a composite model last. This
last is one upon which a leather shoe would not be
made; it is larger, for the rubber shoe must fit over
the leather shoe. Then begins the work of an artist.
The designer must trace the outline of the bottom to
get what he knows as the bottom pattern, and then
he must work up each step in the rubber, taking care
of two points : the style and the effect of wrinkling
and bending, in order that all parts of the shoe work
together in action. When the last is finally designed
and tested so that the shoe made from it is found to
fit exactly, and the style is right in the best judg-
ment both of the last designer and the manufacturer
of shoes, the manufacture begins.

The manufacture of light shoes employs the funda-
mental principles by which heavy boots, arctica,
gaiters, and other types are made; for these all differ
only in detail. Shoes are made of rubber mixtures and
cotton fabric, or rubber mixtures and woolen fabric,
since warmth in winter is important, particularly in
the arctics which have become so popular. In its
essentials, the rubber shoe industry consists of a proc-
ess by which the rubber mixture, sheeted to the proper
thickness, assembled with fabric, and cut into the
proper form, is laid by skilled workmen piece by piece
upon the last, so that in its unvulcanized condition
there is formed a perfect rubber shoe with all the mark-
ings, the corrugations of the sole, the band around the
top, that make up the finished shoe. In a rubber shoe

THE REIGN OF EXJBBER

factory, one is impressed by its intricacy; there seem
to be many different hand operations. Each of these,
however, ia essential; and all parts come together in
the making-room from different preparation rooms.

The rubber compounder who makes up the formulaB
for the different compositions has, after years of ex-
perience in this oldest of the divisions of the rubber
industry, found that certain mixtures give maximum
service. Since appearance plays a large part, he has
found himself limited. Rubber shoes, as a whole, con-
tain only small percentages of sulphur, to avoid bloom.

In the plant, the operations start with a soling cal-
ender. The compound, which contains rubber and the
various strengthening and coloring pigments, will
have been mixed in the mill room in the way in which
all rubber mixtures are made. It is then taken to
the calender room, where it is warmed on the warming
mill and fed into a four-roll, small-sized, rubber shoe
calender. The idea of the four-roll calender is to per-
mit the use of an embossing roll, for the three-roll
calendars used in larger articles deliver the sheet of
rubber smooth on each side. Big rolls are housed in
heavy framework; and naturally, were they to be
removed at any time, it would be a long, difficult
operation. Therefore these soling calenders have
been made small in size, capable of delivering a long
sheet of composition in width a little greater than the
maximum length of the sole for any large-sized rub-
ber shoe. Different styles for different purposes re-
quire slightly different markings on the bottom. H
you will examine your shoe, you will find the grade
numbers, the name of the maker, and little variations

FOOTWEAE AND CLOTHING 175

in the corrugations, indicating different styles and
shapes. Upon the fourth roll has been cut by an arti-
san the depressions which will produce these raised
conformations on the sole, and the rubber is embossed
by this roller as the sheet passes between it and the
adjacent one. To permit different types of impres-
sions, there are usually several of these embossed rolls.
By means of easy locking devices, and since it is small,
the enbossing roll may be removed readily and an-
other one substituted.

The sole is one of the fundamental parts sheeted
on the calender to the required thickness. As it runs
out in a long strip, workmen cut it up in sheets of the
proper length and put it in ** books,'* which consist
of boards with sheets of cloth attached on one side
to prevent the layers of rubber from sticking together.
In another, but slightly larger calender, may be run-
ning at the same time the thin sheet of the ** upper"
compound. This thin sheet will have marked upon it
by the embossing roll the outline of the upper, the out-
side part of the shoe that goes around the foot above
the sole. In still another calender may be running si-
multaneously cloth, wool, or cotton of the particular
weave needed, upon which is being laid friction, the
soft rubber composition forced into the interstices of
the threads. The fabric may also be coated. Here we
We the sole, the upper, and the fabric parts. I have
not mentioned the various other small but important
parts that go to make up the shoe: the little trim-
mings, the reinforcing parts or stays, the insole, the
heel, all of which are made in different rooms, for va-
rious purposes. Since there are many parts and many

THE REIGN OF RUBBER

sizes of each shoe, there must be many workmen an<3
many machines.

Only the three fundamentals — sole, fabric, and up-
per — are here considered. These pass from the calen-
der room to the various preparation rooms where
skilled workmen, or in some eases machines, cut oat
these several parts into the particular shape required.
Finally, these numerous compositions and shapes are
assembled in the making-room in accordance with a
"ticket" or plan previously made. A given number
of shoes a day requires a large number of parts. Tk
making of the ticket in the shoe factory is an important
operation of management. This ticket must show al
each step in the operation the proper quantity or nnm-
ber of each part for each type of shoe, so that honr
by hour and day by day the parts will come to the
making-room in the necessary amounts, with no delay
to the shoemakers. In one of these large, well-lighted
making-rooms, you will find lasts in number and sizes
specified by the ticket.

The shoemaker's one duty is to lay upon the last
in the proper order these different parts. Since the
insole is next to the foot, or leather shoe, as the case
may be, while the fabric that is to serve as the
strengthener lies at the bottom between the insole and
the outsole, the first operation is that of laying the in-
sole upon the bottom of the last. Outside of that is
placed the fabric lining and reinforcing pieces. Then
the upper is applied and rolled down, so that it exaetly
and tightly fits the last. There it is stuck definitely to
the other parts and set to the height and points of
shape that the designer has intended. Finally the out-

FOOTWEAR AND CLOTHING

177

Bole is laid on and rolled down, usually a layer of
cement having been put upon it that it may stick
tightly to its adjacent rubber. The outsole ia care-
fully forced by a roller in the hands of this skilled
operator around the edge and over the upper, the
operation making a neat outside binding. Each type
of shoe is constructed a little differently, and yet here
Ilea the crux of the whole thing: the bringing together
of these different-shaped rubber pieces upon a pre-
Wouely designed last, with the shoe thereby formed
definitely to the shape intended.

After they have been formed upon lasts, these
iight-weight rubbers are put upon trucks and pushed
out of the making-room into another room where sev-
eral at a time are dipped into a bath of a special var-
oiah, the purpose of which is to give the rubber shoe
the high polish that is -so desirable. Any grade of
famish would not accomplish, the .desired purpose;
for it might come out of the vuleanizer with a motley
Colored sheen or dull. Years of experience have de-
veloped this varnish to withstand heat and the action
**f sulphur without change of color.

After they are varnished, the shoes, still on their
*Q-8t8, are returned to the racks on the big truck and
^I'e pushed through another room into the vuleanizer.
Tjiis vuleanizer is, in reality, a large room containing
^team coils that serve to heat the air in the room, the
tot air in turn supplying the heat to the rubbers and
So vulcanizing them. Thus the rubber shoe is vulean-
iZed in what we call dry heat, that is, in hot air, by a
Carefully regulated temperature over a period of sev-
eral hours. When this time is completed, the trucks

THE EEIGN OF BUBBER

stitnte a considerable part of the use of rubber as
foot covering, for in 1919 there were 19,896,000 pairs
of these canvas shoes with rubber soles.

The fundamental principles of manufacture are es-
sentially the same as with rubbers, except that in-
stead of a rubber upper there is a canvas upper.

Apparently Walter B. Manny, in 1891, first sug-
the use of rubber heels. In the last ten
years, and particularly during the last five years, the
use of rubber heels on leather shoes has grown to
astonishing proportions. They are resilient and soft
enough to take away the effect of the blow of the foot
as the heel strikes the pavement, removing therefore
considerable jar from the body and giving comfort
to the wearer. They are longer in life than leather.
Therefore we find that an industry which was too small
to be reported in the census of 1914 had grown in 1919
to the extent of 138,468,769 pairs of rubber heels and
a value of $14,238,000, a development which could not
have taken place unless these heels possessed definite
value to the wearer.

What becomes of these rubber heels f The Census
Bureau answers the question and propounds another
when it says that the production of leather shoes in
the year 1919 totaled 275,357,206 pairs. Thus, about
half the leather shoes are equipped with rubber heels.
Whyt Because, while the shoemakers are in the
leather business, when the wearers come to know the
health and comfort to be derived from rubber heels,
every one will demand and receive them on Ms
leather shoes.

The manufacture of rubber heels is typical of that

FOOTWEAR AND CLOTHING

of other molded rubber goods. The rubber mixture
is sheeted out in about the thickness of the heel. Un-
vuleanized blanks are stamped out of this sheet by '
dies in a power-driven punch press. The raw heels
are inserted into molds, which consist of either two
or three pieces, design plate, form plate, and cover.
Molds have raised lettering or designs engraved in
the plate. In place of the necessary holes for nails
or screws, steel pins of corresponding shape are
screwed in. Design and form plates are provided
with guide-pins, so that the heel form fits with the
lower plate. The thickness of the form plate corre-
sponds with the thickness of the heel. Before the hot
molds are filled, they are brushed with a solution of
soap to prevent the rubber after vulcanization from
adhering to the steel.

The vulcanization of rubber heels is effected in
hollow-plate presses like those used in the laboratory,
except that they are larger. So that an equal pressure
may be applied upon the molds, the platens must be
parallel to each other. The presses are used in bat-
teries of a dozen or more, the steam in each of which
is automatically controlled. After the vulcanized
heels are removed from the molds, the rind is trimmed
off. The resulting rubber heel is to the human foot
what the pneumatic tire is to the automobile.

The modern rubber sole is an achievement of rub-
ber compounding and manufacture. Nearly all the
mixtures have in them a certain percentage of wool,
cotton, or leather fiber mixed with the rubber and vul-
canized. The compound is mixed in the usual way in
the mixing mills, sheeted on the sheeting calenders

•

THE REIGN OF RUBBER

to a correct degree of thickness, cut out to the approx-
imate shape of the finished sole, and vulcanized in a
Bole mold of the nsnal character, for the necessary
time and at the proper temperature, the mold being
held together by hydraulic pressure. There are va-
rious kinds of unusual types, such as soles with inserts
of strands of stout cord under the ball of the foot and
at the heel; there are special ones with knurlings or
corrugations on the soles, although these are not
widely used.

No sooner had crude rubber come into the European
markets than every practical man who worked upon it
tried to make garments. The old English stage-
coaches had outside top-seats; and since England is
so rainy a country, it was natural for the men who
traveled from Manchester to London, desiring to keep
themselves dry and warm, to study how this new sub-
stance could be used for the purpose.

Many attempts were made in the years after 1790;
but it remained for Charles Mackintosh of Manchester
to find it possible to "dissolve," as he called it, rub-
ber in coal-tar naphtha, to apply it to cloth for water-
proofing purposes, and out of the cloth to make a
garment. This was the first practical rubberized gar-
ment made; it was named from the inventor "Mackin-
tosh," a word that has come into the English vocabu-
lary. That great pioneer of the rubber industry,
Thomas Hancock, became a business partner of Mack-
intosh in 1833, and much of his study had to do with
attempts to improve the rain-coat. Indeed, the first
practical application of the Parkes method of cold
vulcanization of rubber by the use of sulphur chloride

FOOTWEAE AND CLOTHING 183

in a solvent was the vulcanizing of the rubber which
bad been applied as a thin layer of composition upon
the surface of these cloths.

Emory Elder, who died May 24, 1884, worked with
Goodyear in Springfield, Massachusetts. He is said to
have been the first to vulcanize clothing, and he under-
went extraordinary trials for want of suitable mechan-
ical means for the vulcanization of large pieces of
goods.

So important was the use of rain-coats considered
during the World War that there was a total purchase
of ponchos, rain-coats, and slickers by the Government
amounting to ten million garments and costing more
than forty-six million dollars. It is an industry to-
day of infinite variety, largely, however, in respect
to the styles of garments and the colors and weaves
of cloth required. Man in his garments seems to wish
variety, and women extensive variety, so that there
are various hues, shades, weights, thicknesses, and
weaves of rubberized garments. Generally speaking,
manufacturers make them in three classes: there are
single-texture fabrics, with one layer of fabric and a
layer of rubber on the inside ; there are double-texture
fabrics, with two layers of cloth stuck together by a
layer of rubber between them; and there are fabrics
with a layer of rubber on the outside.

In the process of manufacture, after the choice of
the proper composition, which depends considerably
upon the quality and service which the particular coat
is supposed to render, and upon the choice of the fab-
ric, the rubberizing of the cloth, so far as single-tex-
ture and double-texture cloth is concerned, is done by

184 THE REIGN OF RUBBER

application to the cloth of rubber in the form of ce-
ment. We still follow the original method in principle
that was worked ont a hundred years ago. A spread-
ing-maehine, as it is termed, is a simple apparatus
looking like a long table, at one end of which is a roll;
above this roll is a metal sheet known as a knife or a
doctor blade. This knife, by careful adjustment, is
set down close to the fabric, which has laid upon it
a certain amount of rubber cement that has been pre-
viously prepared by churning the mixed composition
in gasolene. As the cloth then passes between the
roll and the knife, a thin layer of cement is laid upon
the cloth. In its travels the cloth passes to the top of
the long table, which really consists of a series of pipes
or steam plates into which steam is forced ; the heat
generated thereby evaporates the solvent. Then the
cloth is rolled np with fabric next to each concentric
layer to prevent its sticking to the adjacent layer.

The operation is repeated untU the proper thick-
ness of rubber is built upon the cloth, when it is, in
the case of single-texture garments, passed on to the
vulcanizing-room to be vulcanized. In the case of
double-texture garments, the layer of cement is placed
upon one side of each of two layers of fabric, and
these two are then unrolled through a doubling-ma-
chine, consisting of two metal rolls under high
pressure, which force the two layers of fabric together
rubber to rubber, so that they stick. As the cloth
issues from the doubling-machine, it is rolled up and
passed on to the vulcanizing room.

With single-texture garments either one of two
processes of vulcanization may be used. The original

FOOTWEAE AND CLOTHING 185 ,

Parkes or sulphur chloride process is one of them.
is is still much employed in Europe and more or
IS 80 in this eonntry. In this process, the rubber
side of the fabric by a continuous movement is car-
ried in contact with a roller, the opposite side of which
1 is turning half immersed in a weak solution of sulphur
\ chloride in either benzine or carbon bisulphide. This
-I p-ves a light, weak application of sulphur chloride to
'^'- the rubber, so that on hanging festooned in a large
"■| room for a few hours, the rubber becomes vulcanized.
ij In the case of the dry-heat method of cure, the fabric
is festooned or hung across bars near the ceiling of
a Bmall room, the air in which is heated by steam
eoila on the bottom of the room. After a few hours
the vulcanization is accomplished, and the fabric is
removed, ready for subsequent operations. Double-
textnre fabric is usually dry-heat vulcanized. The
rubber-surfaced fabric such as you see upon police-
nien and firemen for protection from water is some-
times made by the application of rubber from a
spreading-maehine, but more usually, I believe, by the
application of a thin layer of rubber in the usual man-
ner on a friction and coating calender, after which
it is dry-heat vulcanized in the way that has been de-
scribed. The result, regardless of the process or pur-
'1 poses for which it is intended, is rolls of cloth with
'i rubber on one side or between two layers.
* From such rubberized cloth, garments are made by
■ manufacturing tailors by methods similar to those
[ used by tailors everywhere. In building up the cloth
into the garment, it is no longer sewed but is ce-
mented together. After vulcanization of the cloth a

THE REIGN OF RUBBER

ber, conld, under heat, be shaped in an iron naold to
the form of a sphere. According to W. Dalrymple iii
"Golf Illustrated," of November 30, 1901, the real in-
ventor of the "gutty" golf -ball, was the Rev. Robert
A. Paterson, for many years principal of the Biug-
hamton Ladies' College in New York State. In 1845
he rolled a lot of gutta-pereha clippings into a ball,
painted it, and used it on the links. One of the first
Scotchmen to use this invention was William H. T.
Peter.

Naturally, many experiments were made with the
new ball. The introduction of it tended to make the
game more popular and somewhat cheaper. The ball
had kinks of its own, as we duffers think all golf-balls
have, one of which was a tendency to ' ' duck. ' ' Gradu-
ally it was found by the more persistent players that
after a ball had been used a few times and been con-
siderably bruised, the flight was better. Balls came
to be made with marks on them, the scoring being done
with a chisel or a hammer, and after a while with the
mold itself. Although it took about six months
properly to season a "gutty" ball, when produced, it
was quite serviceable and distinctly eeonomieal ; for it
could, when worn, be remolded.

The game in the early days became so popular that
an ordinance was introduced into the Scotch Pariia-
ment in 1457 decreeing that "futball and "golfe" were
not to be played at some certain periods that were
set apart for training in archery. During the four
hundred years following, the game remained almoet
entirely in its native land. Even in 1875 the royal
and ancient game had made very little progress south

CHAPTER Xn
BROADENING THE FIELD OF SPORT

Sport requires quickness of mind and muscle. From
arliest times, the snappiest substance was chosen for
ports of different kinds. Long before rubber was
iseovered, ball tossing was indulged in. More than
our thousand years ago, in the twelfth Egyptian
yuasty, the throwing and catching of balls was
nown; and we find that the early artists sculptured
uman figures engaged in this sport. A leather-cov-
red ball was used in the games on the Nile more than
arty centuries ago, and one of these early specimens
as a place in the British Museum.

Using a leather-covered sphere stuffed with hair,
Le Greeks played baU. One can imagine that not
any home runs were batted with such a dead ball.
be Greeks believed in symbolism, for they played
is ball-tossing game primarily in spring, to typify
e emerging into life of nature after the gloom of
inter. Later the princes of Europe played the game,
I probably many others did, who could afford either

make or to purchase the balls. But South Ameri-
n Indiana bad an advantage over the people of
urope, for the ball that they used was lively rubber;
le game therefore was more interesting.

The American sport of base-ball, it is generally he-
aved, was founded by the Knickerbocker Club of New

188 THE BEIQN OF RUBBER

York in 1845. The earliest regulations, formulated in
1858, specified that the ball should be composed of In-
dia rubber and yam, covered with leather. To-day the
baae-ball is built up around a rubber and cork core,
weighing one ounce and properly vulcanized and
molded in spherical form. Upon this is wound woolen
yam at a definite tension; the ball is covered mth
carefully tanned, selected, tough leather, sewed in the
way that all Americana know. This combination of
wool, rubber, and leather, which weighs between eight
and eight and three-quarters ounces, is the thing the
home run kings bat over the fence; it is what maiee
possible a game enjoyed by millions; it is the best-
known article that contains rubber.

But this it not the only respect wherein rubher
serves the great American game. In the old days, the
intrepid catcher caught the ball or it hit him; but then
the ball was pitched with less speed and fewer baffling
curves than now. Later it became necessary for him
to be armored with a body-protector made of rubber
covered with fabric and blown up tight enough with
air to absorb the shock should the ball strike it. There
is many a catcher who has sent up a vote of thanks
to rubber for protecting him against serious injury.

Let us turn now to another great and popular game.
Base-ball is played by comparatively few but seen by
thousands. Golf is played by thousands and seen by
few. It is estimated that there are in this country
more than 500,000 golf players, playing on about 2,500
courses. In the year 1921 there were very close to
7,200,000 golf-balls made and sold in this country. It
has truly become a popular game.

BROADENING THE FIELD OF SPORT 189

There is considerable doubt just when and where |
the game of golf originated. Some authoritieB con-
tend that the game is of Scotch origin; others say it
began in Holland. Some believe the word "golf" ia
derived from the Teutonic word KoJbe, meaning club,
or from the Dutch word Kolf. One thing, however, we
do know ; the game was in some form played in Scot-
land as early as 1353.

The first ball used was egg-shaped and made from
beech wood; the club was carved from one piece of
wood and shaped something like the present hockey
elub. The modern golfer, who loves the smooth green
and the exactly spherical ball, to be sure of accuracy
in putting, would indeed find himself lost in the at-
tempt to putt an egg-shaped piece of wood with a
hockey club. In those days there were no regular golf
courses or any particular places of play. The players
nflaally agreed on a starting-place and an objective.
The contest was to determine which player could drive
his ball to a certain object in the shortest time, and, in
some contests, to arrive at a destination in the fewest
number of strokes.

Since all games change and progress, it was not long
before the wooden ball was superseded by one which
Was made of hard-pressed feathers with a leather
cover, and which was but a little larger than the pres-
ent ball. So far as skill in its hand sewing was con-
cerned, the cover was a work of art. It is stated that
so many feathers were packed into one of these email
bails that if released they would more than fill an or-
dinary hat. Feather balls were used until 1848, when
it was discovered that gutta-percha, a relative of rub-

BROADENING THE FIELD OP SPORT 193

later the "bramble" or "pebble" surface marking was
adopted, with further improvement in trueness of
flight. Through its snappiness the new ball brought
with it the necessity for lengthening all courses. Hits
that were laid out for the average players were made
to look ridiculous. Irons came into use where drivers
and brassies had formerly done the work.

As time went on, longer and longer flights became
possible from more and more scientific construction of
the center and the cover of the golf-ball. Such rapid
changes worried the officials of the golf associations
who feared that the courses might be reduced to a
mere drive and a putt. To curb the tendency to-
ward excessive length of flight, for no man knows how
far it might be possible to develop a golf -ball by means
of the modem science of the rubber industry, the
United States Golf Association and the Royal and
Ancient Association of Great Britain joined together
and agreed that the golf-ball must not exceed 1.62
ounces in weight or measure less than 1.62 inches
in diameter. The styles of marking were left matters
of choice.

The modern golf -ball is one of the most delicate, in-
tricate, and scientific articles made by the rubber in-
dustry to-day. It is composed essentially of three
main parts. The center or core contains a heavy
material such as lead, to give proper weight and thus
influence the length of drive, and is usually mixed
into a soft mixture. If you examined the photograph
of a section of a golf-ball that has been frozen and
sawed in two, you would see how large a part is
occupied by this core. Many substances, steel, hard

THE KEIGN OF BUBBEE

rubber, soft doughs, stiff pigments, even liquids, are
found in some of the many brands. Around it are
layers of rubber thread of several sizes, widths, and
thicknesses. This rubber thread is made of the finest
rubber and sulphur composition that the chemist caii
produce. Around the thread is then molded a gutta-
percha cover. Not only must the cover be as resistant
as possible to the edge of an iron, but it must be soft
enough during the molding operation under heat to
amalgamate with the outside layers of thread. The
markings on the cover are carefully designed ; for if
they are too deep the ball will soar, if too shallow the
Sight will he low, if none at all the ball will duck.
Balls of the same weight and size, the same core con-
struction, and the same thread tension, molded in the
same way, will show different distances by several
yards when the indentations in the cover are of dif-
ferent number, size, and depth.

The painting operation of a golf -ball is one of those
intricacies necessary to its proper construction. A
good golf-ball paint is not one that can be bought from
any paint-shop ; it must be chosen carefully. It is re-
quired to adhere to the gutta*pereha cover even when
the ball is distorted or when it is struck with the edge
of an iron. It must therefore be flexible and resistant
to blows. It must not change color in the sun; it most
not crack; and it must not be so soft that it will slow
down the ball on a sand green by picking up sand.

Perhaps one of the most important phases of its
manufacture is the accuracy with which the core is
made and the correctness with which the thread and
other parts are applied, in order to make sure that the

BROADENING THE FIELD OF SPORT 195

ball may be true to center. Only a truly spherical
ball, with the center of gravity in the precise center,
will give true flight and accuracy on the putting green.
In the long course of manufacturing development
that has produced the modem goK-ball, there have
been many processes perfected. The original Haskell
patent described "a golf-ball comprising a core com-
posed wholly or in part of rubber thread wound under
high tension and a gutta-percha enclosing shell for the
core of such thickness as to grive it the required rig-
idity." This problem of winding thread under tension
was no easy one. Therefore the invention of the wind-
ing machine was one of the most important steps in the
development of the golf-ball as we know it, and to-
d&y these better-than-human machines work rapidly
and accurately.

The first stage in the manufacture of the golf-ball.
coasistB in the formation of the soft center. Upon
this is wound a tape of vulcanized rubber. This core
is then taken to the winding-machine ; and upon it as
a center there is wound the vulcanized rubber thread.
A power-driven device does the winding. In the ma-
chine the ball center is revolved upon a variable axis
that moves enough and at regular intervals so that the
thread, which is carried around by the machine and
Unwound from a shuttle, is wound in different great
circles npon the core and evenly distributed over the
entire body of the ball. As it passes from the spool
the thread is stretched and wound upon the golf-ball
nnder an exactly regulated tension.

The flight of the golf-ball in play is partly de-
pendent upon the degree of tension applied to the

I
J

THE REIGN OF RUBBER

thread while being wound. The prevailing practice ie
to stretch it almost to the breaking-point. Rubber ie a
peculiar substance, in that it is easy to stretch a con-
siderable distance, but more and more difficult to
stretch slightly farther distances. In golf-ball manTi-
facture the thread is put under that tension which
brings it up to what may be called the difficultly
stretchable part. This gives it the maximum practi-
cal tension. Some balls are wound under high tension
and some under lower tension. The floaters and the
more durable balls generally, so far as the cover is con-
cerned, are wound under lighter tension; they there-
fay have less length of flight. Because the thread is
placed upon the core under the maximum tension, the
high-tension balls are harder, feel heavier under the
blow, and travel greater distances. There are many
different kinds of winding-machines, all of them, how-
ever, having for their purpose uniformity of tension
and proper spherical shape.

After the golf-ball has been wound to its precise
size and inspected to make certain of size, weight, and
tension, it is taken to the molding-room, where the
cover is applied. Several methods are used. By one
of them these covers are first formed in two hollow
hemispheres in a preliminary molding operation.
The mold, which is made of metal, then has one of these
hemispheres put into it, the rubber ball placed in that,
the other hemisphere placed on top of it, and the top
half of the mold applied. The mold is then put into
a hydraulic press, heated with steam, and warmed.
When the gutta-percha is soft, the halves of the mold
are brought together by hydraulic pressure, the action

BROADENING THE FIELD OF SPORT

forcing the soft gutta-percha into the outside
of the thread and into the markings of the mold.
After the proper time has elapsed, the steam is turned
off; and, to cool the mold and the ball, water is then
tamed into the hollow plate, the cooling making it pos-
sible to remove the ball from the mold without injury.
When hot, the cover is soft; when cold, it is hard and
firm. After removing the ball from the mold, the op-
erator cuts off the slight excess of cover squeezed out
between the two halves of the mold.

The ball is then examined again for accuracy and is
sent to the room where it is painted. It requires
several coatings of paint before the right quantity is
applied. After the ball is dried, the different colored
paint is put into the lettering to indicate clearly the
manufacturer's name and brand.

There are three characteristics that make the golf-
ball what it is to-day. It must be constructed in a way
to give under the proper blow of a club a long and
true flight. Secondly, it must be sufficiently hard and
heavy so that on a putting green a fairly firm tap of
the club is required to give the putt direction and ac-
curacy; for a light-weight ball is inaccurate on the
green, and in the approach shot it will bound off the
green if too light and snappy. Thirdly, the cover-
resistance must be sufficient to make the ball durable
under reasonably severe playing conditions.

The flight of a ball is influenced by several different
conditions: the temperature of the air, the barometric
pressure, the humidity of the air, and the wind veloc-
ity. Golfers as a rule find wind to be the only obvious
condition that influences their play beyond, of course,

layers ^^M

THE REIGN OF BUBBEK

their own muscles. A golf-ball is, therefore, very much
in the position of a projectile to be fired from a cannon.
In a recent interesting article by Innis Brown in
"The American Golfer" a comparison is made between
the effect of wind and air resistance upon golf-ballB
and cannon-balls. Temperature also plays a distinct
part. In certain tests made in England, the same
balls driven by the same meehancial device traveled on
an average twelve yards further in May than in Jan-
uary. A considerable part of this flight was influ-
enced not by temperature in so far as resistance of
cold air on the ball is concerned, but by the effect of
temperature on the rubber thread. Rubber thread
is snappier in hot weather than in cold. Therefore
the flight is longer in the hot weather than in cold.

The markings on the surface of the ball have been
mentioned, for they influence flight very particularly.
These influences have been studied in recent years by
scientists, and it is now clear that different types of
markings give different effects. Nothing flies well
without some degree of spin; rifles are grooved in
order to give spin to the projectile, which otherwise
would wabble in flight. Arrows are given a directional
character by a tail ; even a kite is balanced in such a
way that it maintains its flight, and the poorest-bal-
anced kite is the one which wabbles the most. Each of
these articles in the air must follow its nose, a differ-
ence in pressure being developed upon one end from
that on the other.

So there is on a golf-bail a pressure greater at the
bottom of the ball than at the top; thus the ball is
acted upon by a force tending to maie it move upward.

™ BEOADENING THE FIELD OF SPOET 199

The difference between the pressure on the two sides
of a golf-ball is proportional to the speed of the ball
in flight multiplied by the velocity of the spin. When
the golf-ball leaves the face of the driver in a well bit
stroke, it travels at great speed. In front of the ball,
the air is under considerable pressure; and from tbia
point of extreme compression to the back of the ball,
the air regains its normal density. Therefore, there
is a disturbance in the atmosphere in the form of a
tube of compressed air. As the ball travels forward,
it creates in a constantly decreasing degree this tube
of compressed air; and the air rushes around the ball,
flowing in and out of the irregularities. These irreg-
ularities thus get a grip, so to speak, on the air; and
the ball is steadied in a remarkable degree during its
flight.

Recently measurements have been made to find out
how much energy is imparted to a golf-ball by the blow
of the club. In this test various golf-balls were
dropped from ditferent heights upon a heavy iron
plate, which bad been covered with a sheet of carbon-
paper, so that the imprint of the Battened region of the
ball was left on the paper. By the determination of the
diameter and area, we learned bow much the ball was
flattened; and from this we computed the amount of
energy required to distort the baU to that degree.

Measurements were also made of the flattening
given to the ball by the blow of the driver in actual
play. The club-head weighed fourteen ounces ; its vel-
ocity was 203 feet a second ; the energy of impact was
computed to be sixty-fi.ve foot-pounds. By compu-
tation we found the velocity of the ball to be about

THE REIGN OF RUBBER

198 feet a second, and the energy stored in the ball as
it left the club-head to amount to about sixty foot-
pounds. This energy is equivalent to the amount of
work one would have to do if he lifted sixty pounds
one foot.

Some further studies were made to find out how
much force would be required to burst a ball when the
load is applied gradually. Is it possible for a power-
ful player striking the ball with accuracy actually to
smash itf One of the standard makes of ball was
placed between the flat steel plates on the head of a
testing-machine and compressed. With a load of
three thousand pounds applied to the ball, it flattened
without breaking to the extent of more than half
an inch. It required 3900 pounds of pressure to cause
the ball to split open. In view of the fact that oal-
culations show a sixty-five foot-pound force for the
average club stroke, it is highly improbable that any
person can burst the ball by a direct blow.

Why is it, then, that balls break? They are not
broken ; they are cut. The edges of mashies and other
irons are sharp; and when this edge strikes the surface
of the cover with the force of a heavy blow, the cover
cuts. Some of the golf players in this country be-
lieve that their game would be much better if they
used the same brand of ball favored by the accurate,
heavy-hitting professional players. The most power-
ful one is the harder ball, for it contains thread so
wound that it has the maximum return force. Being
hard, this type of ball is readily cut when topped with
an iron club. The reason for this can be demonstrated
by a simple experiment. If you will place a sheet of

' BROADENING THE FIELD OF SPOET 201

paper upon a piece of glass or any hard surface and
press upon it with a knife-blade, you will find that it
cuts through very easily. If you put under it a wide
mbber band and press the blade with the same force,
you will observe that the paper does not cut, because
the rubber band yields. The golf-ball with the most
resistant cover is usually the one that is the softest
wound, for the ball inside the cover yields under the
force even of a cutting blow. This yielding gives du-
rability to the cover.

Since the long-driving, powerful ball yields less eas-
ily to the light blow, this property permits it to be dead
on the green, a fact which conduces to accuracy in the
approach shot and in putting. For the average player,
the difference in distance to be gained between the
hard and the soft wound ball is negligible. In fact,
the light hitter will gain more distance from the softer
ball. The game is won, after all, by the ordinary
golfer not on excessive lengths of drive so much as on
accuracy in approaching and putting. We can, how-
ever, gain longer flight by the choice of balls a little
softer wound.

How long should a golf -ball last T Most of them last
until they are lost. Since the rubber thread is an ex-
actly made rubber composition and is protected from
the action of the air by means of the cover, there is no
reason why the internal part of the golf-ball should
not last for many years. The cover is durable and
reasonably permanent; the paint is inclined to dry
and on old balls to check when struck with a club.
It is probable, therefore, that the present construc-
tion of golf-balls is such that they all should last as

202

THE KBIGN OF RUBBER

long or longer than any player is able to use them.

Another important nse of rubber in sport is in
the tennis-ball. A British army officer is popularly
credited with the invention of the game of lawn-
tennis. His original idea was a game to be played on
a court shaped like an hour-glass, sixty feet in length
and thirty feet in width at the base-line. Tennis is
essentially a modern game; its genealogy is rather ob-
scure. The first record of any such game in Europe
occurred sometime in the middle ages, when a crude
form of it was a popular sport of the European
nobles. The French game was played with a cork
ball which was struck by the hand and driven over
a bank of earth serving the purpose of our modem
net. It flourished in England for a number of years;
and was introduced into America probably about 1874,
when rackets rather awkward in shape were used and
the balls were made of uncovered rubber, similar to the
toy balls of children. The balls were later covered
with flannel and then with felt.

The tennis-balls now universally used are made of
rubber of a resilient composition. This composition
is made into the form of a sheet upon a sheeting cal-
ender. It is then cut in sections, like an orange
peel after quartering. Carefully cutting the edges
at an angle or skiving them, girls cement them,
and press them together. The ball is then placed in
a hollow steel shell or mold. Before this, however, a
little water or other blowing material is put inside.
The ball is then placed in a curing-press and heated
with steam. The steam causes the water or ammonia

BROADENING THE FIELD OP SPORT 203

to blow and force the rubber against the walls of the
mold. During valcanization, therefore, the pressure
developed by the steam is sufficient to keep this rubber
against the inside surface of the mold. After vul-
canization, the ball is removed from the mold and
gaged for size, A hollow needle is stuck through it
at a little point where a self-healing bit of rubber ex-
ists on the inside of the ball; through this hole the
ball is blown up to the proper pressure, about ten
pounds to the square inch. The ball is then slightly
roughened on the surface and covered with cement,
and a layer of flannel is carefully applied. It is then
ready for packing.

There are several other methods of manufacture in
detail, each of which aims at the end of exactness in
shape, weight, size, and durability.

The size and the weight of these balls have not been
varied since the beginning; the laws on both sides of
the ocean prescribe them to measure two and one half
inches in diameter and to weigh two ounces. Great
care has to be taken that the rubber part of the ball
be not porous; although under the best of conditions
nitrogen and oxygen diffuse through rubber, and the
ball gradually loses its life. It is a remarkable fact,
however, that of all the gases that might have been
chosen, the constituents of air are those which diffuse
through rubber the least readily. If carbon dioxide
had been used, for instance, tlie bfe of the tennis-
ball would be much shorter than it is at present.

There is a prescribed standard of resilience. If
balls are dropped from a height of ten feet, they rauat

k 1

THE EEIGN OP EtJBBER

rebound not less than five nor more than six feet. The
game is a fast enough one as it is, without making the
snappinees of the ball too great.

So one could go on with various other sports. The
hand-ball of the gymnasium is a beautifully constructed
spherical ball of strong, lively rubber. There are
also the squash-balls. Polo employs a rubber ball and
hockey a rubber puck. In foot-ball there is the rubber
bladder inside the leather case; the players are pro-
tected by rubber nose-pieces and ear-guards. The
basket-ball is a sphere of carefully softened and shaped
leather, inside of which is a rubber bladder blown up
to tension. Even in billiards the cushions upon which
the player depends for the return at his chosen angles
are a most carefully worked out rubber composition of
high resiliency and of great permanence. Here is no
particular question of durability, for the action of
billiards is not one of an abrasive or wearing char-
acter, but there is a question of permanency and re-
siliency. The moment the billiard cushion becomes
even slightly dead, the skilled player can determine
the fact, and the accuracy of the game is reduced.

In the realm of sport the use of rubber products is
essential to most games. They surely would be dead
and lifeless without it.

CHAPTER Xm

POWER AND LIGHT

He eimple little thing, small in size, easy to make,
BBed in thousands of forms, brings into the home,
tamed, a mighty force. By it power to move moun-
tains is controlled, the dark places are made light;
hy it the waters of Niagara disrupt the rocks and de-
liver them as aluminum pots and pans into the kitchen ;
hy it coal is made to drive the trains rushing through
the smokeless tunnels and the trolleys over city streets ;
by it the invisible force of electricity lights homes and
streets. It is insulated copper wire.

Our school children scuffle along on the carpet in
the winter and surprise their mothers with a spark
on the back of the neck. They play with frietional
electricity, known in the year 941 b. c, when the
Greek philosopher Thales, on rubbing the natural fos-
silized resin known as amber, found that it took on the
property of attracting light bodies, such as straw and
feathers. From the name of the tears of Heliades,
called "electron," came in later years our name
"electricity."

The kind of electrical discharge, however, which
made necessary some type of insulation is the electrical
current that "flows," as we say colloquially, along
metallic conductors or wires. This type of current

206 THE REIGN OP EUBBEE

was discovered in 1780 by the Italian anatomist Gfal-
vani. He and Volta discovered how electrical currents
may be generated and the fact that they flow from place
to place through wires.

When the induction-coil was invented, by which mag-
netic forces could be generated through the mediiam of
coils of wire, it became necessary to provide some
means of insulation; that is, of separation of wires, so
that the different strands would not come in contact
with each other and thus cause the current to flow by
the most direct path rather than through the entire
length of wire. When the brilliant British scientist,
Michael Faraday, in 1831 discovered that a current of
electricity could be induced in a coil of wire either by
moving the wire away from a magnet or toward it,
or by moving the magnet toward the wire or away
from it, there began the development of that marvel-
ous machine upon which our greatest electrical devel-
opments rest, the dynamo, and its brother, the motor.

The first dynamo, made in 1832, was constructed of
a length of insulated wire wound upon two bobbins
with soft cores. Step by step, these machines have
grown and changed, until from them have come our
high tensions and vast transmission systems. The fact
that a dynamo could be reversed and run as a motor
was known probably as early as 1838, but the value of
this reversibility does not seem to have been realized
until 1873.

Now alternating currents generating at high pres-
sure from 2000 volts up to 11,000 volts are produced
at almost any power station. In the United States
currents have been conveyed to places one hundred or

POWER AND LIGHT 207

more miles from the station, at pressures as high as
120,000 volts. Usually, however, the generation is at
lower voltages ; for pnrposes of transmission they
are changed to high voltages by step-up transformers
and then stepped down in step-down transformers
for use at or near the point of reception.

Insulation is, therefore, a basic necessity in electrical
work. The heat generated in dyuainoB and motors is
too great and the space available too small to permit
of rubber insulation. In the generator revolved by the
water or the steam turbine, rubber is not used for wire
insulation. The high-tension wires that stretch cross-
country like great spider-webs are bare. But as soon
as wires come close together in cables to lead elec-
tricity into your house, rubber insulation becomes at
once a necessity. Rubber is high in insulating value.
It is strong, durable, and flexible.

In the manufacture of insulated wire, there is a cer-
tain procedure characteristic of this particular use
of rubber. A trip through a wire factory would lead
us to observe a number of cleverly worked-out proc-
esses. A mass of copper is "drawn," as they
say, or forced in molten condition through a small hole
or die to form the wire. It is passed in continuous
lengths through a furnace, where molten tin is laid on
in a thin layer for the purpose of protecting the copper
from the deteriorating action of the sulphur in the
rubber, for copper combines directly with sulphur to
form a black sulphide. After the wire has passed
through the bath of tin, it is coiled rapidly upon
by an automatic process, in lengths usually from
thousand to five thousand feet.

passed ^^B
spools ^H
m one ^^|

THE EEIGN OF RUBBER

Let us go with theae spools of copper wire into a
room where they are placed upon racke, ready to be
covered with rubber insulation. For this purpose a
tubing-machine is used. Unwinding from the spools
rapidly, the copper wire passes through an apparatus
known as the insulating head of the tubing-machine.
The wire is drawn through two holes in either end
of the head, each a shade larger than the wire itseH,
By the pressure developed by a slowly turning screw
within the cylinder of the tubing-machine, the rubber
composition, softened by warming on a mill, is forced
aroimd the wire. Thus, as the wire is drawn through,
rubber is forced around it, the exact amount of rub-
ber being controlled by the size of the die from whicli
it issues. This insulating head makes it possible com-
pletely to surround the wire with uuvulcanized rub-
ber composition. From this die, the wire is carried on
to a machine which covers it with talc, that in the nn-
vulcanized or sticky form the wires may not stick to-
gether. Then carefully wrapped upon a large drum,
it is ready for the next operation, vulcanization. This
big drum with several miles of wire upon it is rolled
into the vuleanizer, a horizontal steel shell. The door
closed and the steam turned on, the heat is created
to vulcanize the rubber. This is the simplest process
for one ply of wire surrounded by one layer of rubber.

But there are many other grades and types of m-
sulated wire for special purposes. When several wires
are to be insulated from each other and all of tbeia
insulated from something else, it becomes necessary
to use other methods in addition to this simple one.
Several of these wires may be coated separately with

POWER AND LIGHT 209

rabber and then, to prevent them from spreading
apart, they all may pass through a braiding-machine
that wraps around them interlaced cotton threads.
The electric light cables, for instance, which may have
in them one ply or two pUes of wire, are not only in-
sulated with rubber, but the rubber itself is protected
by a layer of braided thread. That, in turn is pro-
tected on the outside by a layer of water-proofing ma-
terial. When two plies of wire are together, as in
what we call the duplex cable, the construction re-
quires a layer of rubber, then a layer of braided thread
around each wire, then a layer of rubber and a layer
of braided thread around the two together; in this
fashion there may be built up many wires, each with
its rubber insulation, with its strength-giving thread,
and with its protection on the outside.

Cable containing a considerable number of wires and
all of them inclosed in a sheath of lead is made for un-
derground work. The application of this sheath of
lead is an interesting process, which is, as a rule, ap-
plied before vulcanization. In a manner somewhat
similar to the application of rubber insulation, the in-
sulated and braided wire is carried into a lead press,
where molten lead under high pressure and very
rapidly applied is forced as easily as though it were
cheese upon the rubber-covered wire, which is pulled
through a die, leaving a quickly cooled layer of lead
on the surface. This serves as a water-proofing and
protecting coat, and is commonly applied to under-
ground light cables and to telephone wires to be
stretched over the city streets.

One of the most important uses to which rubber in-

THB BEI6N OF BUBBEB

w ptf is for railway signaling purposes,
•f eleetricml signals npon railroads is so
— ■^'■g that it is necessary to make cer-
«in Ksed is in all respects uniform and
has come the development of ex-
dfai^HS for th« insnlated wire, drawn up by
Ajssoeiation in cooperation with
Where speed and number of trains are
I aatomatie Uock signaling systems are
in all railway operations. Out of the
bs of block signals installed in the United
to 1919, 36,600 of them were automatic. To
■Btnbun the antomatie system of block signals, the
iMck is ilivided into blocks varying in length from a
flUw htutdred feet to several miles, the distance depend-
iklt <tt ^ speed of trains and the physical conditions,
operate these block signals by means of an
earrvut flowing through insulated wires strung
utMlfP ih» rijdtt of way. the return circuit running back
ItevUf^ the nul& The various signal circuits are
(t ^ W Md or aiBsed fan- e«mt»ets so arranged in combina-
IJHk ^a^ a^nal vire as to apply electrical energy to
patM* w hm conditions are safe for train
TW aigaal aim is countei^eighted, so
IkMl wkWMWr tt» sqEMl drcoits are deenergi2ed it is
\)hnTli lu> tt» hiiri'— tal or "stop" position. It will
iNkl^ WSIMWtt* nwtifl or ''proceed'' position when
ft eoaditioD which means that the
t[V«}k ijiiKW^ ai* WBM^pKd and ail the electrical re-
tHi,\ vHHttoct» arw «ltw«tl in the block over whidi the sig-
HtU )ty^v(tk» tibM tzsin. taovements.

POWER AND LIGHT 211

If anything should happen to the electrical clrcnits,
all signals would automatically asaume the stop posi-
tion until the signaling system itself could he put in
order. All switches on the main tracks or sidings in
use in this automatic territory are provided with cir-
cuit controllers. Such details have been carefully
worked out. If the side-tracks have upon them a car
or an engine ao close to the end of the side-track as
to foul a main track movement, there will be an elec-
trical reaction that will operate the semaphore stop.
The insulated wire controlling this mechanism in all
sorts of weather is vital to the safe operation of the
trains ; this constitutes one of those great and import-
ant usea to which rubber insulation is put.

From the beat of data, the first block signal system
in this country was put into operation by Ashbcl Welch
of the United New Jersey Railroad and Canal Com-
panies in 1863. This was considerably later than the
introduction in England, which was as early as 1842.
"The Scientific American" states that the automatic
block signal was invented in 1871 by Thomas J. Hall.

To show the degree of care which surrounds the
manufacture of this kind of insulated wire, one may
note a few of the items from the specifications de-
veloped by the Railway Signal Association and upon
the basis of which the manufacturers of wire are
obliged to work. They vary as to quality of the copper
wire, but insist that it be uniform in size and com-
position. The rubber insulation must be made of a
eomposition in which are used only the best of rub-
ber and those ingredients which conduce to uniformity

THE BEIGN OP EUBBEB

of strength and aging properties. The braidiog ii
carefully regulated; and, snbsequent to manufacture,
a series of tests is performed npon the wire to make
sure that each coU of it has the proper strength, both
as to wire and rubber, and proper electrical conduc-
tivity. The wire is examined to see that the ri^
amount of tin has been applied, that the braiding aaA
the waterproofing have been properly done, that the
rubber insulation is of the right tensile strength,
and that various other properties adapting it to the
purpose for which it is intended are present. The in-
solation is then thoroughly tested for electrical prop-
erties, to make sure that there are no leaks, pin-holes,
or other defects. Thus every possible eflfort that in-
telligence can bring to bear is pat on this insulation '
material to make it approach perfection.

The wires that bring the current into your house
are rubber-insulated in the same careful way, subject^
however, to a slightly different code of regulations
than have been mentioned for the railroad signal wire.
In this case, it is the insurance companies that protect
yon; for the main risk that is run by electrical wires
coming into the house is that of short circuits which
might produce sufficient sparking to set fire to wood-
work. There have been many cases known in which
mice and rats have gnawed through the insulation of
copper wire, causing the bare wire to come in contaoi
with wood. Most modem houses have the wires car*
ried through iron pipes known as conduits; and th«
code of regulations permits also the use of porcelain
insulators to keep the wires a certain distance apart.
Thus danger from lightning, from sparks jumping

POWER AND LIGHT 2131

From one wire to another and igniting the woodwork, ,
and from short circuits is avoided.

When building a house, it is wise for a householder '
to look personally into this important part of the
construction. Electricity is a servant when controlled.
Be careless with it, and it may be master. Not much
damage is done to appearance if some of the hidden
brickwork or masonry does not strictly conform to spe-
cLficationa; but it may save considerable expense if
the electric wiring be properly installed under the
most careful supervision and in accordance with the
most rigid regulations that municipalities can adopt.
Workmen may err; look over your own electrical in-
stallation, and make sure that no insulated copper
wire is in contact with woodwork. See that porcelain
insulators of sufficient length are used; then you will
be taking the most vital precaution possible in the
building of your house — that of preventing any acci-
dental baring of copper wire> with its subsequent short
circuit and probable fire.

Copper wire brings the electricity into the house;
rubber is the protection used, and the best protec-
tion ; for its flexibility, high insulating properties, uni-
formity, and long life serve to make it the ideal one
for this purpose. It does, however, gradually harden
with age. For the user to examine carefully the
electrical wires that connect lamps to sockets and, in
particular, to examine the wires that connect the vac-
uum-cleaners and other devices that are moved around
the house, is a wise precaution. For as the wire
wrinkles and bends, in the course of time the rubber
may break and thereby expose the wire, the exposure

replace these I

214 THE REIGN OF RUBBER

leading to short circuits. One should replai

wires often enough to make certain that the insulation

is always in the best of condition.

The early dynamos produced current at low volt-
ages of 110 to 200 volts. As the transmission lines
were extended, the central station in a small city lost
a great deal of power, both from heating of the con-
ductors on account of resistance and from leakages.
In the development of this important engineering sci-
ence, as the years have rolled on, the voltage or ten-
sion at which electricity is transmitted has become
greater and greater, until to-day central power sta-
tions, such as those at Niagara Falls, customarily send
out over the wires electric current at many thousand
volts, and several wires, as a rule, are strung over the
same electric pole system. Because it is inadvisable
to shut down all wires while the workman may repair
one of them, proper protection is vital to his safety.
The electrician high up on a power-line pole sur-
rounded by death-dealing, high-tension wires is in no
ideal situation. He mnst be protected against the
power of the live wire while he repairs the dead one.
So he throws over adjacent wires a rubber blanket
on each side of him ; and he works in security.
These blankets are made of a highly uniform rubber
composition ; they have high dielectric strength. Each
one is carefully tested for its resistance to puncture
with a high-tension current; that is, two terminals
from the secondary coil of a high-voltage transformer
are placed on each side of the blanket and the voltage
is raised until the spa?k jumps through. Thus the
voltage is measured at which a spark will penetrate

POWER AND LIGHT

215

the rubber blanket. The blanket mnst resist the pene-
tration of a spark at high voltages.

We see the man who changes the carbons in the
arc-lights on our city streets, as well as the repair-
man of high tension lines, wearing rubber gloves. It
is necessary for him to be able to handle the wires with
impunity; certainly he could not do good work if it
were necessary to incase his hands in porcelain gloves.
Here Charles Goodyear comes to the front again; he
made the first vulcanized rubber gloves to protect
electrical linemen. Being flexible, rubber is generally
used throughout the electrical industry, where we find
linemen and others wearing heavy gloves made of
a pure, uniform rubber composition that is nearly
perfect as an insulator. The lighter weight gloves are
usually tested to resist puncturing or against exces-
sive conductivity of current up to four thousand volts ;
those used in high-tension circuits are thicker and are
tested to withstand ten thousand volts. They give
excellent service until wear and repeated creasing
across the palms cause cracks to develop; then they
are either repaired or new ones are purchased.

Care must be taken in testing linemen's gloves, or
in repairing them, for they must above all things be
non-conductors of electricity. Each glove at the fac-
tory is tested for breakdown or dielectric strength.
For this purpose, a glove is placed in a copper case
open at the top and with an opening at one side
through which the thumb projects. The glove is then
nearly filled with water and immersed in an iron buc-
ket filled with water. Inside the glove an^ outside of
it, there are placed electrodes connected with high-

THE REIGN OF RUBBEE

tension current. This current is increased up to the
point where the glove fails.

Heavy rubber gloves are all made on fundamentally
the same principle; that is, a form of tin or steel is
made the shape of the band. Workmen, usually
women, Jiuild sheet rubber upon it around the fingers
and the hand. The glove is finally placed in a mold,
pressed, and vulcanized.

I have spoken of wire and the transmission and
use of power. Manifold are the uses of electricity,
and with them rubber insulation. The ignition system
of automobiles, the hot days cooled by the swiftly ro-
tating fan, the electrical adding-machine in factory,
office, and store, vacuum-cleaners, the breakfast
toaster, form a host of conveniences. We feel civil-
ized by means of electrical power. Without it how
bare would our lives become! And without rubber,
we should lose the use of most electrical appliances.

CHAPTER XIV

COMMUNICATION

The rubber hydrocarbon is a versatile substance.
Combining with small quantities of sulphur, it yields
soft, vulcanized rubber. It keeps its secret, however;
for apparently no chemical compound, as the chemist
technically terms it, is formed with any of these small
amounts. In any event, the chemist admits his igno-
rance as to just what soft rubber is. When thirty-two
parts of sulphur, though, are mixed with one hun-
dred parts of rubber and vulcanized over a long
period of time, — six to twelve hours, — there seems to
be formed a combination with fixed properties, which
chemists behave to be a definite chemical compound,
expressed by the formula CioHieSg. The compound
is hard rubber or ebonite.

The inventor or discoverer of hard rubber was Nel-
son Goodyear, a younger brother of Charles Good-
year; and the first hard rubber patent was that granted
to him on May 6, 1851. He had assisted his brother
in experimenting with rubber; but he had, to this time,
made no important contribution of his own. Because
the need for some such substance had attracted him, he
set out to get it. He mixed "one pound of caoutchouc,
half a pound of sulphur, and half a pound of magnesia
or lime or carbonate of magnesia or lime or sulphate

THE BEIGN OF RUBBER

of magnesia and lime." For vulcanization he speci-
fied three to six hours or longer and a temperature of
260 degrees or 275 degrees Fahrenheit. His speciflear
tions claim the combining of India rubber with sul-
phur, either with or without shellac, for making a hard
and inflexible substance, hitherto unknown.

Thus Nelson Goodyear was to the hard rubber in-
dustry what his brother Charles was to the soft. On
March 22, 1852, he granted a license to Conrad Pop-
penhusen for the use of his patent in making imita-
tion of whalebone; and in July of that year he died.
His estate was managed by a third brother, Henry B.
Goodyear. In 1858 the patent was regranted and was
issued in two parts; various suits were sustained in
favor of the Goodyear patent.

At first hard rubber was considered a substitute for
ivory. In the early history of the business, too, the
demand for hard rubber to incase the magnet of the
ordinary relay and for other uses in connection with
the telegraph field gave it a great impetus. Then it
was stimulated by the telephone, the druggist sundry
lines, and buttons. In 1851 the India Rubber Comb
Co. of New York was organized for its manufacture,
with a factory at Williamsburg, Long Island, and later
a factory in Hamburg, Germany.

Hard rubber and soft rubber have ever worked to-
gether. Probably no better illustration of this cooper-
ation can be given than in the case of the telephone.
It was in 1873 that Alexander Graham Bell in a Boston
attic made the first telephone, a crude box-like affair,
about as much like the desk telephone of to-day as the
stage-coach is like the aeroplane. A great many years

COMMUNICATION

219

elapsed before his invention came into general use.
Now in the city of New York alone there are more
than one million telephones in operation.

In a recent report of the American Telephone &
Telegraph Co. the statement is made that during the
last ten years the investment in plant and equipment
has increased from $672,500,0U0 to $1,569,000,000.
During the last twenty years, while the population of
this country has increased only 45 per cent., the number
of telephones has increased about 900 per cent. In
1921 there were more than 13,380,000 stations in this
telephony system, constituting approximately two
thirds of all the telephones in the world. Two and a
half million telephones serve the farms in this country.
At the end of 1921 there was a total of 27,819,821
miles of Bell-owned aerial and underground wire, an
increase of something more than two million miles
over 1920. We are now able to telephone across the
continent.

It was on June 2, 1875, when Dr. Bell was studying
transmitter rings on the telegraph instrument in the
room of Thomas A. Watson, that the idea occurred
to h JTn that if the vibration could be heard over an
electric wire so could the voice. He developed the
idea. Great strides upon the original invention of Dr.
Bell, but with many additions, have been made. The
part that rubber plays is generally that of an in-
sulator, a protecting cloak that keeps the feeble cur-
rent within bounds and prevents it from going astray
from the metallic path laid out for it.

The story of the efficiency of rubber begins the
moment yon use the telephone. The instrument on

220 THE KEIGN OF RUBBER

the desk has mach metal in its construction, through I
holes in which the wires ran, bnt from contact with \
which they are insulated by hard robber bushings.
The instant the receiver is removed from the hook
on the instrument, au electrical contact is made. The
current, always ready Ln hard rubber storage batteries
like the horses in the fire-station, flashes over the wires
to a light at the switch-board in the exchange, thaa
signaling to the girl operator that you would have
speech with her. The American switch-board opera-
tors made a remarkable record during the war in.
France. They are the best trained in the world, and
the most courteous. The operator grasps the metal
plug, incased in its hard rubber and connected witti
its cotton (not rubber) insulated wire, and pushes it
into a hole lined with metal in tjie bank of the switdi-
board and in contact with the flexible metal parts of
the jack. The light goes out, llut tjie electrical con-
nection is made and you tell her your desires. The.te
jacks to which the individual lines are connected are
set in hard rubber, ten jacks to a bank. The parts
of the jack are insulated by thin hard rubber sheets,
about ten to a jack. Each of the thirteen million
stations appears on a switch-board several times.
Literally millions of little, important, hard rubber
parts assist the accuracy of telephone converaation.
Hard rubber is a firm, strong material, superior in in-
sulating properties, which with ease and accuracy can
be sawed, drilled, or machined^ The transmitter of
the telephone on the desk and the parts of the receiver
are hard rubber because of these very properties of
strength and insulation. Some new substances have

COMMUNICATION

|»w entered this field; it will be interesting to see

'liich lives.

The wires on the telephone and the intricately ar-
ranged forests of them on the switchboard are not in-
sulated hy rubber, or are the large lead-eovered
cables stretched from pole to pole or underground in
tile eondnits, but by cotton thread impregnated with
w&x. -Bui from pole to house in the open, and
from lightning-arrester inside the house to the bell
box, rubber-covered wire seems necessary to with-
stand the action of light and weather. In short, where
resistance to the elements or where the demands of
insulation are high, rubber is the one most trustii
worthy material.

In no place has the rubber-insulated wire seemed
to demonstrate its value more than during the war,
where the part played by the telegraph and telephone
was remarkable, — more so than most people realize,' —
for the telephone connections that were strung over
the western front hy the mile were the means of com-
mnnication between outposts and headquarters. In
the World War messages over insulated wires, in-
stantly delivered, took the place of the man on horse-
back or the runner on foot. There were men on motor-
cydeB and there were runners on foot, to be sure ; but
the great majority of signals and communications were
over modem telephone systems.

Crowell and Wilson state that the outpost wire In-
sured secret communications at the front; it was a
twist of two wires, each single wire being made up
of seven fine wires, four of bronze and three of hard
carbon steel. Stranded together, these were coated

CouitEsy of Westtm Elwi

COMMUNICATION

225

^^taken. Possibly in the future vulcanized rubber
may be used for any purpose with assurance of per-
manency.

Yet a new brand of communication has come among
us. The use of the radio telephone in connection with
aeroplanes, the development of direction finders, mak-
ing it possible for ships at sea to ascertain in a fog
their exact direction with reference to lighthouses,
the use of the internal aerial in homes, and the perfec-
tion of receiving sets, making it possible for one in
his home to listen to broadcasted concerts, lectures,
and reports, form one of the remarkable electrical
developments of this age. Its end is not yet. So great
has been radio development that confusion in the air
has made probable a limitation by legislation of the
number of sending stations. Since continuous waves
of different frequencies, that is, at different lengths,
may be sent, a classification of possibilities has been
made, with the result that very soon the sending
stations will probably each have its own definite wave-
length or frequency. Thus a remarkable means of
communication will rapidly be systematized in a way
to avoid interference.

Since these waves travel through the ether at the
speed of light, 186,000 miles a second, one can sit in his
house, tune his receiver to receive the voice of a
speaker in a large auditorium, and actually hear the
words more quickly than those in the rear of the audi-
ence. Sound-waves travel at the rate of 1090 feet
a second. A person a thousand miles away will re-
ceive the voice in one one-hundred-and-eighty-sisth of
the time the sound will require to reach a man a thou-

THE REIGN OF RUBBER

sand feet away from the speaker. A voice has been
heard across the ocean ; signals have been heard at the
antipodes.

The part played by rubber in radio development is
marlied, for today the aerial may be made of a single
strand of insulated copper wire instead of one made
of a bare wire. The insulated wire throughout the
circuits in a house, the hard rubber storage-battery
cells, the hard rubber used in condensers, in panels
of receiving sets, in the dials, and in other places, are
all notable developments which assist in making the
radio possible.

One of the numerous uses to which hard rubber is
applied, and one of the greatest of them in the pressEt
day, is the hard rubber cell for storage batteries.
This prince of our rubber realm serves in many ca-
pacities. When the electrical starting and hghting
systems were developed for automobiles, they called
for the use of a storage battery; this has led to a high
development of the hard rubber cell for this purpose.
Storage batteries to supply current at even voltage
without noise form part of the telephone system and
of radio installation. In the earlier days, glass was
used. But glass is too friable a substance for an auto-
mobile running over a rough road, and too difficult
to make precise enough in shape to economize space.
Therefore, the hard rubber battery cell has come to be
generally used. Its value lies in its strength and
lightness. Some day if you will examine your storage-
battery, which unfortunately most of us fail to do
often enough, you will find it to be, in many cases, a
wooden box containing three and sometimes four nar-

COMMUNICATION 227

row cells or boxes of hard rubber. Each of these has
a hard rubber cover or top that fits tightly into the
cell, resting upon a little shoulder molded into the rub-
ber. The manufacturer of the cell then usually fills
this space with a soft plastic composition to prevent
the splaetiing over of the cell liquid.

Whether the battery cell be of the size used in the
automobile,— about a foot high, with a wall probably
an eighth of an inch thick, — or whether it be a huge
one made for the storage-batteries of the submarine) —
frequently five feet high and over two feet square, —
the principle of manufacture is essentially the same.
First there is made a lead and tin alloy, which is cast
in a mold to the exact size desired for the inside of
a battery jar. When this comes from the mold, it is
called a mandrel or form. It is made four to sis
inches longer than the jar, in order to give a sufficient
manufacturing leeway.

After the compound is mixed, it is calendered to
the proper thickness, and sheets of the rubber com-
position are cut so that the length of the sheet con-
stitutes the distance around the jar and the width con-
stitutes its height. In the manufacture of a battery
cell, therefore, the workman first places in the end
of the mandrel, in the spaces provided for them,
triang:ular-shaped pieces of unvulcanized hard rubber
to form the lugs or supports for the grids or metal
parts inside the cell. These are often known as
"bridges." In order to have a permanent support
for the lead members, it is necessary that the lugs be
vulcanized to the jar. When these are put into spaces
provided by the mandrel, the workman covers them

THE BEIGN OF EUBBEE

with a layer of hard rubber composition that is of the
exact length and width of the bottom of the jar. This
is usually somewhat thicker than the side wall material,
because of the necessity of having the bottom well sup-
ported. Around this mandrel, then, is wrapped the
layer of composition, and it is carefully overlapped
and rolled together so that no leaks can occur at the
seam. It is then turned over the bottom part, and the
comers are all careftdly rolled down to avoid
"leakers."

In many of the hard rubber ceUs, in order to give
them a high polish, a sheet of tin is wrapped around
the outside of the cell after the layer of rubber has
been applied. In some instances, the sheet of tin is
rolled upon the side-wall composition before its appli-
cation. Recent methods require no tin; for, after all,
the user of the hard rubber cell never sees the cell it-
self, and the expense of polishing it is an unwarranted
one. After the hard rubber battery cell is thus com-
pletely formed in its unvulcanized condition, it is
stacked upon the shelf of a small truck, which is
pushed, when loaded, into the shell of a horizontal vnl-
canizer. With the vulcanizer door closed, steam is
turned in, and the cells are vulcanized. In the old
days it required eight to ten hours to vulcanize even
these thin layers of hard rubber; in modem days com-
positions have been developed which permit of vulcan-
ization in as short a time as three hours.

The making of the covers for the hard rubber bat-
tery jars is a simple process. Pieces of rubber of the
right thickness and width are placed in one side of a

COMMUNICATION 229

Hold. The other side is then adjusted so that
when, under hydraulic pressure, the two sides are
brought together, the rubber, being soft, flows and fills
all of the cavities in the mold. Then it is heated to
the proper temperature and for the necessary time to
vulcanize it into the required form. "When removed
from the mold, after inspection and trimming of the
slight excess that has flowed from the mold into what
is termed the rind cavity, the cover is ready for ship-
ment.

Rubber manufacturers make only these parts o£
the battery. The battery manufacturers assemble the
rubber parts, together with the electrolyte, the lead
plates, the grids, and the paste. In other words, the
rubber man makes the rubber parts ; and the battery
man assembles them into the battery. When the
battery is assembled, the terminals that pass through
the holes in the cover must be surrounded with hard
rubber so closely that the liquid cannot splash out.
For this purpose, as well as for a stopper between the
terminals through which electrolyte can be added or
removed, hard rubber is used.

Although several different substances have been de-
veloped to take the place of bard rubber for battery
cell work, thus far none of them has superseded it,
largely on account of the superior strength and light-
ness of the hard rubber mixture. The Germans dur-
ing the war were obliged to use other substances,
particularly for their submarines, but without complete
success. These large submarine battery jars are made
up in essentially the same way as the little ones;

THE REIGN OF RUBBER

that is, calendered sheet rubber is built up about a
large form or mandrel until there results an unvul-
canized jar.

There are manifold other uses, of course, to which
hard rubber is put; electrical switch-boards, fountain-
pens, combs, — indeed, thousands of articles. Truly,
in the field of communication, rubber as insulation for
wire and hard rubber for telephone uses work in per-
fect unison.

Business methods of to-day, though, demand more
than the telephone and the telegraph. Conversations
are confirmed by mail ; orders are written down ; con
tracts are prepared and signed; records of transac-
tions and agreements must be permanent. Memory
is too frail a thing upon which to erect the structure
of business intercourse. Therefore, in the oflBce the
stenographer is queen, where the business man is king.
In the realm of commerce, during the reign of rubber,
no more important servant exists than the typewriter.

The first typewriter of which we have record waa
patented in England in 1714. In 1829 an American,
W. A. Burt, patented what he called a "typographer";
and about 1833 another kind was produced in France.
Again in 1844 and 1846 tj^iewriting machines were de-
veloped in England. From then on to 1850 there were
a number of English modifications. A. E. Beach in
1847 constructed a fairly successful instrument, which
utilized the principle finally worked out in the modem
machine, that of a basket of levers arranged in a
circle, delivering their impressions to a common center.
He never perfected the machine, however. The
names of Sholes, Soule, and Glidden, of Milwaukee,

COMMUNICATION

are really connected with the modern typewriters, for
upon their ideas, developed from 1868 and 1873,
the Remington typewriter was constructed. In thia
instrument the short arms of levers were connected by
wire rods with levers proceeding from the keyboard.
The paper to be written upon was passed around a
rubber cylinder, the lower side of which received the
impact of the type face while an ink ribbon intervened
between the type and the paper. This is the principle
underlying all machines as they are to-day.

Nearly seventeen hundred patents have been granted
on many hundred machines, each employing the
rubber cylinder or typewriter platen. This rubber
shell or platen is to the typewriter what the pneumatic
tire is to the automobile. It receives the blow of steel,
softens the shock to just the right degree, and yet is
hard and uniform enough to permit a true impression.

Typewriter platens are made of a peculiar sort of
rubber composition, capable of vulcanizing neither into
hard rubber nor soft rubber, but into an intermediate
grade. The rabber compound can contain only sub-
stances capable of the finest state of subdivision; no
particles of grit must show through the surface to blur
a letter. The platens are vulcanized to a tested hard-
ness. If they are too soft, the impression of the letters
upon the paper will be blurred; and if too hard, the
paper is liable to be cut or the type injured. Through
compounding and vulcanizing, the maker must obtain
an exact degree of hardness.

Would it not be comfortable if in our communica-
tions we could compose our thoughts and exercise onr
fingers to make no errors in writing? We do make

THE REIGN OF KUBBER

to make any desired lettering or wording for a rubber
stamp very quickly. Rubber stamp-making is a little
industry by itself in every city in this country. Tlie
operators who make the stamps prepare molds by t!ie
use of what they call a matrix compound — a quick-set-
ting mixture of mineral powders, into which, while
soft, the impression of the steel type is forced. An
unvukanized rubber compound of the size and thick-
ness desired is then laid in sheet form upon this matrix
when it is set and dry. Pressed in a steam or electri-
cally heated mold, the rubber is forced into the letter-
ing in the matrix and vulcanized. After vulcanizing,
the set of rubber type is removed, and the stamp is
trimmed and mounted upon a sponge rubber backing
on a wooden block with a handle.

Rubber stamps are numerous ; in fact, they are as in-
dispensable to the business activities of the world as
the telephone, for they are tremendous time savers.
Small as the stamps are, it has been estimated that
the rubber-stamp manufacturers of the United States
employ fifteen million dollars in capital to produce an
annual output evaluated at about five million dollars.

Though strikingly different in physical properties,
each of these two forms of rubber, hard and soft, plays
its joint part in extending the range of speech, in
bringing ideas near at hand, and, like the brothers who
invented them, in quietly laboring in the interests of
mankind.

CHAPTER XV
FIGHTING FIEE

"Venite, pueri, eamus ad ignem!"

The boys of ancient Rome stood around on street
comers, waiting for sometliing to happen, just as our
small boys do now. At the clang of a fire-bell, if it
was used in those days, the boys probably rushed off
with a "Come on, boys; let's go to the fire." The fires
of Rome were not easy to put out. "While the flames
curled out of the windows, the small boys might have
seen men stretching hose made of the intestines of
oxen. For a fire-engine, a few men sat heavily on a
skin filled with water, and so forced a tiny stream upon
a second-story blaze. So says the architect Apollo-
dorus who wrote in the time of the Emperor Trajan,
about 100 A. D. These means accomplished little, but
they expressed an attempt to control fire.

The Romans probably fought fires with other crude
engines that delivered meager streams of water
through some kind of pipes, but history is somewhat
obscure. Pliny the Younger speaks of the sipho as a
fire-engine of some sort, but no hose was known. The
ancients, even two hundred years before the Christian
era, recognized the need and made crude engines to
throw water.
-The earliest record of flexible hose is in the writings

THE EEIGN OF RUBBER

of Herodotus, who says that the Persian Cambyses,
who invaded Egypt about twenty-four-hundred years
ago, was obliged to camp in, the desert, a twelve days'
journey from the river Corys. In order to keep his
followers supplied with water, the monarch made pipes
of the skins of beasts and through three different lines
brought water to the camps.

Concerning early use of hose with fire-fighting ap-
paratus, Professor Beckmann, writing in 1801, says,
"This invention belongs to two Dutchmen, both
named John van der Heide, who were inspectors of
the apparatus for extinguishing fires at Amsterdam.
The first public experiments were made in the year
1672, and were attended with so much success that at
a fire in the nest year the old engines were used for
the last, and the engines with movable hose for the
first time. In the year 1677, the inventors obtained an
exclusive privilege to construct engines according to
their principle for twenty-five years."

Great savings were made by using the new appa-
ratus to extinguish fires. The hose was constrncted of
leather, thick enough to withstand the force of the
water. The leather hose was screwed upon the en-
gine, the end of which widened into a kind of bag sup-
ported near the reservoir, and kept open by means of
a frame ; laborers poured water into the bag from
buckets. The Van der Heides, however, for this pur-
pose employed a pump, which they called a "snake
pump." How it was constructed has not been re-
corded; it was probably a cylinder with a lever.
Every leather pipe employed for conducting water was
called a "water-snake," The water-snake was not

FIGHTING FIRE

made like the hose of the fire-engine, of leather, 1
of sail-cloth. It is said, however, that for this purpose
the sail-cloth required a peculiar preparation, which
consisted in making it water-proof by applying a cer-
tain kind of cement. The hose through which the
water was conveyed had to ^te stiffened by metal rings
also; othenrise the external air on the first stroke of
the pump compressed the hose so that it could admit
no water. Seamless hose was made of hemp in the
year 1720, in Leipsic, and in 1801 at Bethnal Green,
near London.

Apparently the first record that we have of rubber
hose, as a definite competitor of these improved leather
pipes was that of a hose invented by Thomas
Hancock and manufactured by Charles Mackintosh i
Co., of Manchester. Experiments were carried out on
board a floating fire-engine belonging to the London
Assurance Corporation in September, 1827. A length
of leather hose and one of rubber were attached to
the engine, each of them furnished with a tightly-closed
plug. After the engine had been worked for a short
time, the leather hose burst in the solid part of the
leather. The India rubber hose remained firm and un-
injured; and the engine itself became disabled by the
breaking of one of its cranks without producing any
effect upon the elastic material. Hancock's hose was
made with an inner coat of unvulcanized rubber; other
layers were applied to the principal folds of the can-
vas.

It was about this time, 1829, that the first steam fire-
engines were built in London; but they were not used
for a number of years because of the prejudice against

;her, but ^^H
purpose 1

THE REIGN OF RUBBEE

them. The London fire-department reported that they
required too much water; that the water might be in-
judiciously applied; and that they were too heavy for
rapid traveling. This prejudice seemed to last until
about 1852.

Rubber hose was a tremendous improvement. It
was necessary to make leather hose from the best part
of the hide. The hose was usually in forty foot
lengths, and a great deal of the work was required to
keep it lubricated with tallow and wax, so that it might
remain pliable. Since rats and mice thrived on the
leather, it was frequently soaked with infusions of
bitter apple. Even though canvas hose had the ad-
vantage of lightness and strength, the wet cotton had
a tendency to decay; it would not stand rough usage,
either. After the days of vulcanizing, at least in Eng-
land, highly satisfactory fire-hose was made by the
North British Rubber Co., for the use of steam fire-
engines, which was strong and well-built, and which
satisfactorily stood tests at the Crystal Palace in 1863.

The invention of the hose-coupling, a most important
part of fire-hose, came from the Van der Heides of
Holland, who have already been mentioned. They at-
tached brass screws to the ends of their fifty-foot
lengths of delivery hose, so that any number could he
quickly comiected together as occasion might require.

In America, the year 1785 saw the organization of
the first fire company; and but a few years later, in
Brooklyn, the first fire engine was ordered from Jacob
Eoome of New York, who had just begun the manu-
facture of engines In America, all the earlier ones hav-
ing been imported from England. Great and strik-

JTig is tbe i KgE»M M e ' Wt»»x» iW M eJera lighapwd,
e&deut matar-ma^ma wmd Ots naet pcimitiTe «»tcr
keg. It ns m ^^ w d f bos bal£^ ISD gaBoAs of
water, wliidi ws poared into it beat backets fiUed «t
wella and cictaas, Aav bei^ bo |»OTisH» mt that
time for proesiiiis wntex by snetaan. nne f«et bi$li.
a eondeasaBg-caae aroee froro the middl? of the box;
and the arms were placed lengthwise of the engiitw.
With the handles foar men eoold work the pum(>s at
each end. From a gooseneck beginning at the lop of
the condensing case ran a six-foot pipe with a three-
quarter-inch opening at the nozzle. Through this [upe,
canted toward the fire, a stream could be thrown sixty
feet. This crude thing was christened "Washington
No. 1."

From then on, the development of fire-fighting ap-
paratus became more and more active. The organ-
ization of fire-departments proceeded as rapidly m
men's minds could accustom themselves to tlie need
for them and to the invention of the iraprovomenta
necessary for the efficient combat of fire. In IhcHe old
volunteer days, which have lived down even to the
present, the entertainment of "visiting flromon"
played a social part in the life of America, as wellf
probably, as a highly influential political one.

There have been large fires. The great London fire
of 1666, fanned by a raging east wind, destroyed a
city; for the only means of fighting fire in tliose dayt
were buckets, large syringes, and crude enginos. The
great New York fire of December, ISSO, shows fire-
fighting methods in striking contrast with the modern
ones. Then the water was so intensely cold that it

jossible. and I

THE REIGN OF KUBBER

rendered efficient working of engines impossible, and
the fire held the mastery; the efforts of firemen were
powerless, because water almost instantly froze in the
engines. Even the hose lines froze.

High-pressure water, with delivery so rapid and sup-
ply 80 unlimited that it has no opportunity to freeze
in the winter, and electric fire-alarm signals to notify
instantly the permanent fire station of the discovery
of the first small fire, mark the changes between the
life of former years and that of to-day. Oar bnild-
ingB are more nearly fire-proof, but enough of them
can bum to call for speed in reporting and answering
the fire call.

The employment of flexible hoae, strong enough to
bear a high working pressure of water, has in no
small degree increased the facilities with which fires
can be fought. In particular, one must not fail to
mention those admirable agencies, such as the Under-
writers' Laboratories in Chicago and the Associated
Factory Mutual Laboratories in Boston, that, in order
to give the highest degree of uniformity to hose pur-
chased from any one of a number of manufacturers,
have developed specifications up to which much fire-
hose must measure. Such great cities as New York,
Chicago, and Boston have made careful study of it in
cooperation with rubber manufactures, with the re-
sult that fire-fighting rubber hose has reached a hi^
state of development.

Up to 1859 in this country, fire-hose, either rubber or
leather, was imported from England ; but in that year
Henry S. Herkener began the manufacture of flat,
seamless woven hose on a few looms. He uaed linen

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r ' ^?^^%

- ' : . -i';^MP^S

i*"'^' "r"' %^P*^

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Vbi^^l

WLl

HMKifll

FIGHTING FIRE

yarns instead of hemp. John Clark of Maiden, Mas-
sachusetts, had a factory for this purpose; and the
New England Linen Hose Co. was also in the field. A
similar hose woven by the Fitehburg Duck Co., some
assert, was the first. This hose soon became popular
for mill and factory purposes, and, to some extent,
for fire-engines in the larger cities.

About this time James Boyd's Sons of Boston man-
ufactured at Doweil a heavy, selvage-edge duck hose,
coating it on the inside with rubber and riveting it
lengthwise in the lap as they had in the case of their
leather hose. This rubber coating was put on by the
Boston Belting -Co. Although it was a bulky, clumsy
article in four-ply rubber construction, it was much
used ; since the heavy working pressure of the steamers
soon made short work of the now antiquated leather
hose.

Cotton flat-woven hose, rubber-coated inside and
then turned inside out, was next manufactured. This,
however, was a failure. By many experiments and
much study, men attempted to find a means of lining
this hose woven in a seamless form. Pouring rubber
cement into the hose and drawing a metal cone back
and forth through its length was one idea. Vulcaniza-
tion, however, was not sufficiently well understood, and
the fiber was injured. Various other schemes were
invented in those days, particularly in the weaving of
circular, seamless fabric.

In 1872 James E. Gillespie invented a circular loom
for weaving a multiple tubular fabric. He, together
with Robert Cowen, a young machinist, worked out
the fundamental ideas ; but the multiple-cotton, circu-

I
I

242 THE REIGN OF EUBBER

larly woven hose was finally abandoned, and the single-
jacket or Btraight-weave was manufactured in its
Btead. The need for fire-hose and the development of
it led to the organization of many companies, among
them the Boston Woven Hose & Rubber Co., which was
bnilt around the ideas of Gillespie and Cowen. J. B.
Forsyth of the Boston Belting Go. finally patented a
process by which the cotton, rubber-lined fire-hose was
made possible.

Cornelius Callahan was another pioneer. He made
a machine for weaving cotton in tubular form about
two inches in diameter, and conceived the idea that it
might be used for fire-hose, although his original
thought was of weaving woolen goods in tubular form.
This hose was lined by the Boston Belting Co. He
then made a fire-hose that was strong enough to stand
the water-pressure. Callahan continued to experi-
ment ; in 1876 he made a double-jacket hose which did
not burst until subjected to a test at a pressure of 1181)
pounds.

Like that of most developments, the history of hose-
making is one of constant change, but the problem now
seems to be settled. Rubber-lined fire-hose in reality
consists of two parts, a cotton jacket and a rubber
lining, the strength of the hose and its flexibility be-
ing supplied by the jacket. This jacket is circularly
woven, a process that means it is built upon a loom by
which a number of cotton threads are unwound from
spools and are woven into the hose parallel to its
length. This constitutes what is known as the warp
and serves the purpose of keeping the strength-giving
part of the hose in position ; for the filling is, in point

FIGHTING FIRE

of fact, a heavy, strong cotton thread that is spirally
and closely wound in one continuous length from end
to end. The loom is so made that the warp or length-
wise-threads are woven in and out among the spirals
of filling. Thus, there is built a seamless, heavy,
strong cotton tube with no rubber in it.

The rubber lining is made of a high-grade rubber
composition — in fact, the highest grade that the rubber
manufacturer is capable of producing for this purpose.
A great deal of experimentation has been done in the
development of the composition. Because it is too
soft, pure rubber cannot be used. The compound used
must be stiff ; it must be strong in tensile strength, in-
dicating the highest quality; and it must resist aging
to the maximum degree, for hose stands in locations
convenient for use, not best for storage. It must also
have those properties that permit it to adhere to the
cotton. Since fire-hose must be in perfect condition
when the call comes, every part of it must be designed,
constructed, and finished accordingly.

In order to put the tube, or "lining," as it is called,
into the circularly-woven jacket, the whole tube is
sheeted on a sheeting calender to proper thickness
and width to make up the inside circumference of a
hose two and one half inches in diameter — the standard
size. In the factory a fifty-foot length of this lining is
wrapped upon a mandrel or folded over by a skilled
workman upon a table, so as to make a tube out of it,
the edges being overlapped and the inside being dusted
with talc to prevent its sticking to itself. This tube
is then carefully laid upon a long truck or metal tray,
which is pushed into a steam heater, where partial vul-

244 THE REIGN OF RUBBER

canization occurs. The purpose of this operation is
to add that degree of strength and stiffness to the lin-
ing which will permit it to be handled in the sub-
sequent operations without distortion or breaks.
After this is accomplished, it is taken back to a table.
Upon the tube is then applied a layer of rubber known
ae the backing — a soft, flexible composition used for
the purpose of assisting in the adhesion between the
lining and the cotton jacket. Thus, in this incomplete
form, the hose consists of a partly vulcanized tube pr
lining with an unvulcanized soft backing cemented to
it.

This rubber tube must now be drawn into the jacket
— a trick done by a clever device something similar to
that by which our mothers force a darning egg into
a stocking, except that in this case the egg is followed
by the tube. Each end of the tube is then carefully
fastened to steam-tight pipes, and free steam is
brought in, which at the pressure used expands the
lining against the jacket. The heat softens the back-
ing and causes it to flow into intimate contact with
the cotton threads of the jacket. During the period
of time, therefore, while steam is blown through the
tube, the rubber vulcanizes. The result is a vulcan-
ized rubber lining in close adhesion to the jacket.
Ready for inspection and the application of the conp-
Ungs at each end, the hose is completed.

Out of the many articles made in the rubber indus-
try, there are few subjected to such careful supervi-
sion, testing, and accuracy of workmanship as fire-
fighting hose. Each length is submitted to a hydro-
static test. During this test, it must not leak, nor must

FIGHTING FIRE

the threads break; it must not contract in length or
diameter; it must not rise from the level of the teat
table. Circular-woven hose has a tendency under
pressure to untwist, with all kinds of peculiar move-
ments. The manufacturer is required so to make it
that these movements will be reduced to a minimum.
Imagine the consternation, if not fatality, to the fire-
men if, when water pressure of 125 pounds came hurl-
ing through a hose, the nozzle in his hand should un-
twist and the hose writhe. He would be thrown off
his feet, possibly off a building. Consequently, fire-
hose must be as permanent and free from movement
as it is humanly possible with the best of machinery to
make it.

Fire-hose, too, must be as light as is consistent with
strength. A fifty-foot length of single-jacket fire-
hose weighs about forty pounds; and the double-
jacket hose, such as is used with the high pressure of
some cities, weighs about seventy pounds. Even this
is no small weight for firemen to drag over the ground
and up ladders.

To make sure that each part of the hose is properly
built, test samples are submitted to hydraulic pres-
sure until they burst; the bursting pressure, which
must exceed on single- jacket hose five hundred pounds
to the square inch and on double-jacket hose sis hun-
dred pounds to the square inch, is measured. Since
the average water-pressure of most fire-departments
does not exceed 125 pounds to the square inch, — some
cities run it as high as 160 and 200 pounds, but this is
relatively rare, — the test gives a generous leeway in
strength. Furthermore, in the system of testing.

ay in i

;, the H

THE BEIGN OF RUBBER

Care in building; care in the use of electricity, gaa,

and matches ; hose at hand in every home to eatch the

inapient fire — all these will help.

^_ We have equipment for eflSciently fighting fire; we

^B have over six million feet of fire-hose ready for instant

CHAPTER XVI
IN THE SEKVIGB OF HEALTH

We may succeed in "outwitting our nerves," but
it is rare to find one able to keep his appendix in order.
He who has joined the fratenxity of the appendixlesB
individuals remembers well the details: the wonder
what it was all about, the feeling that be must have
eaten something that did not agree with him, finally
the examination by the grave physician and the smil-
ing surgeon. A perfectly simpl& thing to the doctor,
it is a journey into an unknown land for the patient.

Once the diagnosis, was made and an operation for
appendicitis was certain, you may remember the rub-
ber-shod orderlies who kept you in a horizontal posi-
tion on the stretcher, while they gently and noiselessly
carried you down and into the waiting ambulance.
Perhaps you were so afraid the offending member
would cut up that you thought little of the part rub-
ber was playing in your affairs at the time. The tires
on the ambulance freed you from jar, — in dangerously
acute cases an item of no small moment, for should
that obstreperous appendix have been broken by a
sudden shock, you would have been in for, perhaps,
disastrous consequences.

Your reception at the hospital was into an atmos-
phere of quiet and seriousness. The noise-absorbing

lOrs of rubber tiling, the rubber shoes on the nurses

I
I

252 THE KEIGN OF BUBBEE

ciate the role that rubber products play during the
operation itself.

The practice of modern surgery constitutes one of
the greatest advances for the well-being of humanity.
There is a tremendous difference between the old meth-
ods and the new. Surgery has been performed for
hundreds of years, war, if nothing else, necessitating
it. Amputations were necessary. In the days of Hip-
pocrates and of the Arabian physicians, there was
little done in the way of cutting for fear of hemor-
rhage. Affected parts usually become gangrenous and
were removed only when they virtually fell off. One
marvels at the fortitude both of surgeon and patient
during the middle ages, when, to prevent hemorrhage
in amputations, the cautery was used. Imagine the
contrast with the methods of the present operating-
rooms. In those days, with no anesthetic, the poor pa-
tient lay in the operating-room,»such as it was, awake to
all that happened. Cauteries were heated in the fire in
another room. Yet, however careful the surgeons were
to hide the apparatus, one can imagine the pain and
the shock of such operations.

Ashhurst in an address entitled "The Patience of
Surgery" makes the remark that "Esmareh (1873)
introduced his rubber tube and inaugurated an era of
absolutely bloodless surgery." While we must not
give rubber the full credit for changes in operative
surgery, yet it came to be one of those important tools
which contributed to the technique of the surgeon.

No one who has been brought np in the school of
antiseptic or aseptic surgery can have any idea of the
horrors that were perpetrated in the name of surgery

IN THE SERVICE OF HEALTH

by our ancestors. The lack of anesthesia in those
days perhaps was an advantage rather than otherwise,
as it limited the scope of operations. During opera-
tions, patients had to be forcefully restrained. The
wards were hotbeds of surgical fever and other mani-
festations of unsanitary methods leading to an appal-
ling post-operative death-rate. Alleviation of pain
came with the discovery of anesthetics (1842-46), in-
volving the names of four investigators— Long of
Georgia, Morton of Hartford, WeUs of Hartford, and
Jackson of Boston, who began to use ether and nitrous
oxide. Finally, chloroform was used in 1847 by Simp-
son in England.

Despite the fact that bacteria were discovered by
the Dutch optician Leenwenhoek of Delft in 1683, and
studied further by many men, including Schoenlein in
1839, Holmes in 1843, Cohn in 1850, and Pasteur in
1858, it remained for the great Lister to apply the
knowledge to operative surgery.

Micro-organisms of various kinds, both pathogenic
and non-pathogenic, are minute vegetable cells that
cause ns much trouble. Early in the hospital expe-
rience of Lister in England he had been deeply im-
pressed with the high mortality from septicemia, ery-
sipelas, tetanus, and hospital gangrene. The fatal
cases were numerous. Those were the days of "laud-
able pus"; yet when his attention was drawn to the
work of Pasteur, he set out to prevent the develop-
ment of micro-organisms in wounds. At that time
gangrene was so common that without pus and sup-
puration surgical operation was considered inefficient.
Where he perceived that sterilization would avail

(

256

THE EEIGN OF RITBBER

the cleanest, finest grades of rubber (smoked sheets,
pale crepe, or up-river fine para) can be used. Before
it is started through any process, the manufacturer
takes excessive care to see that this rubber is free from
dirt, chips, or any foreign material ; for these little
particles of foreign matter would cause holes, and a
hole in a surgeon's glove makes it useless and brings
danger both to the surgeon and the patient. There-
fore it is customary to wash this rubber with great
care and to dry it by the methods which maintain the
maximum of its natural toughness and resiliency.
The rubber is masticated for a long enough time, in a
mixing-mill that is comfortably warm, hot not hot.
Modern chemistry has shown that masticated rubber
or rubber softened by mechanical action readily forms
a thin cement when mixed with a solvent. In making
surgeon's gloves, in order to limit the number of dip-
pings required for a given finished thickness, it is ad-
visable to have a well-softened rubber.

In the case of toy balloons some coloring material
is used, red, blue, yellow; but in the case of surgeons'
gloves no color of any kind is utilized. For a solvent,
a pare grade of gasolene is employed, but one that
does not volatilize too rapidly. It must be pure and
free from waxes and high boiling ingredients, for these
would be left in the rubber after evaporation. In the
best factories, the rubber, after weighing, is cut into
pieces of convenient size and placed in a fairly large-
sized, revolving, drum-like apparatus known as a ce-
ment mixer. This is tightly sealed to avoid loss of
solvent. As the gasolene swells it, paddles inside pull

IN THE SERVICE OF HEALTH

and tear the rubber, which, gradually becoming weaker,
forms a sticky mass of cement.

In a tall tank the cement stands aboat twenty-four
hours, until any impurities have settled. The solution
in the upper half is drawn off and strained through a
fine-raesh brass wire screen. Then the cement is car-
ried on to a tank called the "dipping tank," in con-
nection with which is used' a machine known as a
"dipping machine." Dipping machines are simply a
aeries of frames arranged over the tanks in such a way
that one frame can be dropped slowly down into the
cement, allowed to remain a proper time, and removed.
They carry upon racks, porcelain forms that look like
human hands. A aeries of different sizes are made,
numbered usually from six to ten, with half -size inter-
vals; although seven, seven and a half, and eight are
those most generally used. In operating the dipping
machines, which may be either intermittent or continu-
ons, the forms are placed with the fingers down upon
racks on the machines. The forms are slowly forced
into the cement, where they are allowed to rest a
moment, and then are removed. With the layer of ce-
ment upon them, the forms are allowed to stand in the
air of a room to dry. At the end of about two and a
half hours, they are dipped again. Thus a thin layer
of rubber is deposited uniformly upon the form. The
operation is repeated from sis to ten times, until the
proper thickness, by this repeated dipping and evap-
oration, is built up.

Because the tacky, sticky, half-dried, unvuleanized
gloves are easily contaminated by dust, insects, or
particles from walls or ceiling, the dipping room must

THE EEIGN OF RUBBER

clean. A well-planned system of ventilation carries
out the solvent vapors and replaces them with fresh
air, without, however, the introduction of foreign ma-
terial. The gloves must be perfectly dry before they
can be passed on to the vulcanizing stage of the proc-
Such conditions as humidity and temperature
in the room are controlled by automatic devices in the
best factories. Suitable thinness or proper thickness
of cement is another important matter cared for by
watchfulness on the part of workmen.

The final drjdng, which follows the last dipping,
eliminates all solvent. Depending upon the weather,
the drying time usually varies from eight to twenty-
four hours. When conditioned air is used, it is reg-
ulated to a schedule. Because dipped goods, like all
other rubber products, are made in definite weights,
careful standardization is attained in the dipping
room by test-weighing materials stripped from forms
as the dipping nears completion. After the dipping
and the drying of the gloves in a finishing room, such
refinements as beaded edges are applied, either by
hand or machinery.

Vulcanization is accomplished by one of two meth-
ods. Surgeons' gloves are usually vulcanized by ex-
posure, in a special room arranged for that purpose,
to the vapor of sulphur chloride at a temperature of
about 180° Fahrenheit during a period of one hoar.
This is a practical application of the cold cure or
Parkes process. During vulcanization it is in foggy
weather very difficult to keep moisture away. Every
care is taken to do so, for sulphur chloride is rapidly

IN THE SERVICE OP HEALTH

259 ,

decomposed by moisture, with a separation of sulphur
and the forming of hydrochloric acid. However, some
forms of dipped articles are vulcanized in a bath con-
sisting of a solution of sulphur chloride either in ben-
zol, carbon bisulphide, or carbon tetrachloride. This
is a weak solution of about 2 to 4 per cent., in which the
article to be vulcanized is dipped and allowed to re-
main for a time varying from fifteen to sixty sec-
onds, depending upon the thickness of the rubber.

After they have been vulcanized the gloves are taken
to a stripping and inspecting room, where they are
removed from the forms, dusted with soapstone,
tested to be sure that they are free from imperfections,
and packed for shipment.

Surgeons' gloves are the finest article of the kind
made. By this dipping process they come to the hos-
pital seamless, with wrists usually reinforced by rub-
ber tape or cord. Since the vulcanization was per-
formed by sulphur chloride, they are entirely free from
any hard substances inside the rubber. This not only
serves to limit the danger from puncture, but naturally
renders true Ihe sense of touch. They are smooth,
although some have been made with a finely pebbled
surface, For special purposes, many of them are
made with long sleeves.

During the course of an operation there are a num-
ber of other rubber articles that play important parts.
Although I have concentrated upon gloves, there are
solutions of specially prepared sterile rubber which
may be applied over the cutaneous surface and thus
prevent the spread of infection. The commonly used

260 THE EEIGN OF RUBBER

protectives developed by Lister included not only silk
protectives, paraffin paper, and so on, but rubber mem-
branes and gutta-percha tissue.

It is a long way from the modem, beautifnlly kept
hospital to the surgery practiced during the World
War, with the sudden changes from place to place be-
cause of troop movement and the exigencies of battle.
It is also a long distance in the practice of surgery
from the methods used in the World War to those
used in the Civil War in this country or in the Euro-
pean wars during the middle of the last century. Ash-
hurst, writing about the great French surgeon Nelaton
(1807-73), remarks upon his wonderful discoveries.
He had the characteristics that have endeared modern
surgeons to thousands of patients; for he stood at the
turning of the ways between the brutality, necessary
possibly, of the older method and the gentleness and
refinements of the new. Ashhurst says: "He wished
surgery to be gentle, and he was happy to thinli
that the patients who forget in after life the
pangs surgery had made them endure, retained an af-
fectionate memory of the surgeon." He invented,
for instance, the soft rubber catheter now in universal
use. It was during his time that Chassaignac intro-
duced the rubber drainage tube (1859). The old war
methods were crude; if they were brutal, it was be-
cause the facilities that havemarked the more gentle
modem surgery were lacking.

As a good illustration of the difference between the
early wars and the present ones, it is of interest to
know about the illustrious Garibaldi, who was
wounded, in August, 1862. The best Italian surgeons

IN THE SERVICE OF HEALTH

' ' explored the wound. ' * Exploration of a wound
meant a painful probing process. They failed to find
the ball, and this great general lay for two months in
an uncertain condition. Finally it was only by the
nse of Nelaton's porcelain-tipped sound that the ball
was located, where he had predicted. Imagine the
change from those old methods to the ones in the mod-
ern wars, by which the location of any foreign matter —
pieces of shell or shrapnel — is inmiediately discovered
with the X-ray apparatus. Frightful as the World
War was, it would have been infinitely more so without
these many refinements ; and the X-ray, while definitely
a discovery in pure physics, is assisted in no small
way by rubber insulated wire.

The use of rubber tubing to convey antiseptic so-
lutions had its most marked advance during the World
War. Many is the soldier who owes his life and
health to the Carrel apparatus for administering
Dakin's solution. The perfection of the Carrel-Dtikin
technique was the most marked advance in the treat-
ment of infected wounds since the discovery of anti-
septic surgery. The experience gained during the last
fifty years from civil, military, and industrial surgery
had contributed very little toward the combating of
wound infection. Because of the character of the
wound and the nature of the infection, the extent of
damage in the great war was far more deep-seated
than in previous wars. So the problem which con-
fronted Carrel and Dakin was the same as that which
confronted Lister. They worked out a mtethod o^
bathing the infected wounds with a constantly flowing
solution. To accomplish the greatest facility in bath-

THE REIGN OF RUBBER

ing wounds of different types, it was natural for them
to torn, as men have for years, to rubber and to rub-
ber tubing as the most flexible tool. Without rubber,
imagine the difficulty of twisting glass to shapes nec-
essary for the treatment of all kinds of wounds.

It would be impossible here to catalogue the mani-
fold uses and services to mankind achieved by rubber
in army medical work. It plays its part in a general
movement emanating from the minds of men in the
field of surgical and hospital practice to make the
patients' lot endurable.

To return to our appendicitis operation, let us imag-
ine the patient in the quiet of a clean, white room, be-
ginning to recuperate. We have spoken of the rubber
drainage tubes, but we find also the hot-water bottle,
the ice-bag, the sheeting on the bed, the elastic band-
ages, the movements of chairs and beds rendered
noiseless by rubber tips, all tending to make him more
comfortable.

Since in the advance of medical practice, as in all
other paths of life, the use of new tools to gain the
end of comfort and health is probably one of the most
important services to be rendered, let us keep our eyes
open to the results of the present and search on for
new attainments. In the words of Ashhnrst:
"To know the wisdom and the accomplishments of the
past, and from them to gain a clearer vision of the
needs and the possibilities of the future; to record
and to study the experiences of the present, and com-
pare them with the learning of others; to recognize
the shortcomings and the disadvantages of current
methods and theories, and to search for better; to let

IN THE SElaVICE OF HEALTH 263

neither feeble health nor prosperity, neither the
indolence of youth nor the procrastination of advanc-
ing years deviate them from the path of learning
and of progress; to prove all things and hold fast to
that which is good : This is the patience of the saints.
This is the patience of surgery.**

May rubber ever play a strong, vital part in the
service of health I

CHAPTEE XVII
BELTING, PACKING, AND HOSE

Belting, packing, and hose are the rubber trium-
virate in mines, mills, and railroads. Machinery must
be driven from prime movers, boilers must be steam-
tight, railroads must run in safety.

For the transmission of power, the rubber belt came
into use in relatively recent years. Probably the
first time was in 1844, when two Englishmen, Alsap
and Forster, patented improvements in elastic fabric
88 driving bands for machinery. Again, in 1858, aa
Englishman named Parmalee worked out the principle
of stitching together two or more layers of woolen ma-
terial which had been previously spread or coated on
both sides with India rubber or gutta-pereha. A
basic patent, this was for many years known as Parma-
lee belting.

Modern factories contain forests of belting. Where
the operations of the machines are variable with re-
spect to load, the electric motor connected directly
to machines has not displaced belting.

In the woods of Maine or in the far Northwest, thi^
planers and the great saws of the lumber mills slash
their way through wet timber, impelled by power
transmitted through rubber belting. Here, with vari-
able loads and wet lumber, conditions are not at all
favorable ; and rubber-covered belting alone see]

alone seem^^^

BELTING, PACKING, AND HOSE 265

stand the irregular service. Of all the types of ma-
terials used for the transmission of power between
moving parts, rubber belting is capable of widest ap-
plication under conditions ranging from the frigidity
of winter's cold to the bpiling of summer's heat.

Belting is a combination of rubber and strong, tough
cotton fabric. The cotton fabric is the backbone of the
belt. The rubber compositions, the sinew and the'
muscle, hold the layers of cotton together and cover
them to give friction-grip upon the pulleys and to pro-
tect them from wear and weather.

In the design of belting the number of layers or
plies of duck and the width and length necessary to
transmit the amount of power required with a mini-
mum of loss and a maximum of life must be deter-
mined. With these data, one who understands belt-
ing can design it for any purpose, in a way that will
give the longest possible life and the most uniform
service. Herein lies one of the evident advantages of
the cotton-rubber belt— flexibility of design. Given
the most difficult installations, a rubber belt can be
made to fit them.

The most important, probably, of the belting com-
positions is the layer of rubber between the plies of
cotton duck. We shall not stop to consider how any of
the compositions is mixed; nor is it necessary to men-
tion the constituents. Belt duck usually comes from
the cotton mill forty inches to fifty inches wide, de-
pending upon the design and the purpose for which it
is intended. It is wound in long rolls upward of 150
yards in length and weighing about three hundred
pounds.

266 THE REIGN OF KUBBER

The rubber composition for the belting is softened
on a warming-up mill. If it were fed to the friction
calender when cold, it would be too hard to flow, even
at the ordinary summer temperatures; therefore be-
side the big calender are mills very similar to the
mixing mills in the mill-room. Upon these an opera-
tor places pieces of the mixture. The rolls squeeze
and work them until they are soft. Pieces are then
cut off and placed between the two upper rolls of the
calender, which move at a slow, steady speed. Thifl
causes the rubber to be sheeted and passed around in
direct contact with the middle roll. The space be-
tween the middle and the bottom rolls is kept at jnst
that amount of separation which will permit the thick
ootton fabric to pass between without crushing. On
the way through, the rubber compound is forced
against it and into the interstices between the threads.
It is wound upon a drum on the opposite side.

Since the middle roll of the calender is moving at
a faster speed than the fabric, it gives the fabric a
wiping action in passing. Because of this the calender
is known as a "friction calender"; and the operation
of applying rubber to cotton duck is called "frietion-
ing." Thus, the first process in preparing belting is
to friction the fabric with the proper rubber composi-
tion.

Rubber is applied in this way to each side of the
long roll of duck; then an additional coat of rubber
is laid on. Rolled up again for ease of carrying, with
a layer of cloth between the plies to prevent sticking,
the rubberized fabric is transported to the belt depart-
ment. In the belt department the operators measure

BELTING, PACKING, AND HOSE 267

off the required length and width ; and by a systematic
method of procedure they lap one layer upon another
until the requisite thickness is built up. Each ply
from top to bottom is balanced with respect to width
and relation to each other ply, so that theTaelt in bend-
ing around the pulley will work as a unit.

The belt is then taken to long vulcanizing presses
heated by steam. Here rolls of uncured belting are
supported at one end of a long hydraulic press.
Several strips of narrow belting together are drawn
through the press upon the surface of the lower plate
or platen. Through hydraulic pressure this lower
platen is raised, so that the belting is gently squeezed
between these two steam-heated, polished, hollow steel
platens. To prevent squeezing it too heavily, guides
or metal strips of proper thickness are laid upon each
side of the belt. After a period of time which varies
according to the thickness and size of the belt, the rub-
ber is vulcanized. Then the hydraulic pressure is re-
lieved, the press plates are separated, and another
length of belting is pulled through. Thus, section by
section, the roll of belting is vulcanized and wound up.

Vulcanization, however, has accomplished the pri-
mary purpose of creating a degree of resistance to sep-
aration of the plies of cotton cloth, that in action pre-
vents pulling apart. Obviously this is the one im-
portant function that rubber performs, and herein its
peculiar character is again remarkably well demon-
strated. There is no other material which applied in
any way gives to such layers of cotton the two prop-
erties necessary for service. These two properties
are adhesion and flexibility.

268 THE REIGN OF RUBBER

One cannot be greatly dissatisfied with rubber when
he hears of the case in one of the lumber mills in the
State of Washington, where a fifty-six-ineh-wide, eight-
ply transmission belt ran from October, 1905, until
April, 1917, or nearly twelve years, although its top
cover was torn off by accident and it was twice sub-
merged in water during flood times. During this
period it transmitted 26,000,000 horse-power-hours.
This is equivalent to an amount of work sufficient to
move a mass of one ton 211 times around the earth.

Rubber belting has been manufactured in the United
States since 1836, even before vulcanization was dis-
covered. It was later a monopoly under the Good-
year patent, controlled by Henry Edwards of Boston.
It became one of the important lines manufactured by
all the leading rubber goods producers.

Since every fiber can be governed during the process
of manufacture, rubber belting is uniform in make-up.
The duck is tested ply by ply and foot by foot. When
the belt is finished, its "friction" can be governed and
tested. Where a belt is required actually to run in
water, as is the case in mines and concentrating-milla,
the rubber belt has merited its extended use. Like
tires, footwear, and other goods, the modern rubber
belt is the result of remarkable evolution in manu-
facturing. The early belts had the inherent faults of
a product of an undeveloped industry ; but after years
of experimentation and study, the virtually perfect
belt of to-day was found ; and it has become a valued
article wherever power transmission is needed.

One important phase in the application of the rub-
ber belt is the fastening of the ends. Proper fasten-

BELTING, PACKING, AND HOSE 269 ^

ing permits the maximum amount of power to be trans-
mitted. It means a steadier drive and freedom from
jerks, flapping, vibration, and aide-sway; for the belt
it means less wear and longer life.

There are various types of lacings to hold the ends
together. Endless belts are built for special pur-
poses ; but they are often made in the field by cutting
back the several plies and lap-splicing them, using rub-
ber cement and either vulcanizing on the spot or dry-
ing under pressure.

Underneath the Pullman car, pelted by cinders and
sand, in winter's cold and summer's heat, runs a belt
that affects us when we travel. It is the axle-lighting
belt, connecting a pulley on the axle of the truck with a
pulley on the dynamo that generates current for the
lights in the cars. It runs continuously day and night,
in all kinds of weather. The service is most severe ;
yet test records show that many of these belts have
run more than forty thousand car-miles, and some
more than one hundred thousand car-miles.

Belting for power transmission is the little fellow
but the eldest of the family. The younger brothers
are larger of stature. They are the burden bearers,
for upon their hacks are conveyed materials of all
kinds. In the mines and smelters in any of the great
mining centers of Montana, Utah, Colorado, Arizona,
or anywhere in the world, slow-moving, heavy con-
veyor belts transmit ore from crusher to concentrator
over relatively long distances.

Thomas Robins was the pioneer of conveyor belts.
He made a suggestion that apparently revolutionized
the conveyor-belt design. Believing that a rubber

THE EEIGN OF RUBBER

cover would outlast many times its own thickness of
cotton fabric, he conceived the idea of a belt with a
thick layer of rubber on one side. After making nu-
merous compounds and testing them with a heavy
stream of ore, he found one that would stand abrasive
wear for the longest time. From then on, he devel-
oped the idea of idler pulleys and the trough-shaped
belt, so that, in point of fact, the ore was continuously
in motion, carried in a moving trough. This idea was
the best fundamental conception of a conveyor belt.
After a good deal of difficulty, he succeed'ed in interest-
ing people in the conveying of iron ore and also of
anthracite coal.

Conveyor belts are made on essentially the same
principles as transmission belts. Heavy cotton can-
vas, frictioned and coated with rubber, is built up in
several phes, so as to be flexible and contain the rob-
ber best able to resist wear. But the rubber is thicker
in the center and the fabric thicker at the edges.
Thus, the most rubber is concentrated where it will re-
sist wear; and the most fabric is placed at the edges,
where it will carry the strain of power. The belts
are easily moved; they may be given concave or flat
surfaces, as the conditions demand; they are light in
weight as compared with metal buckets ; they show a
minimum of wear from friction on the rollers, as com-
pared with buckets traveling in chutes : all these prop-
erties have made extensive installations of conveyor
belts a necessary part of many mining operations.
The design of these belts for special purposes is a mat-
ter of engineering construction and is different with
nearly each installation, for various kinds of ore, for

BELTING, PACKING, AND HOSE

2n^H

of mar ^^H

Biirt t.Vifi "

particular speed, for the weight and the type
terial. The duck must be strong and flexible, and the
rubber adhesion must be maximum during the life of
the belt. The rubber cover must resist heat, for many
materials are hot ; it must resist abrasion, for the ore
particles are sharp-edged.

In the mines of the copper companies in Salt Lake
City, there are installations of belts three hundred and
more feet long, a yard wide, which have delivered more
than seven million tons of ore. In conveying sugar in
California from evaporator to warehouse, belts four-
teen hundred feet long and thirty-sis inches wide have
operated continuously over nine-year-periods and de-
livered during that time eight billion pounds of sugar.
To charge gas retorts, belts carry coal from bin to
charging machinery over distances as long as thirteen
hundred feet. Some belts weigh more than fourteen
thousand pounds. The presses in which these giant
workers are vulcanized have, in recent years, grown
to thirty feet long and eight feet wide.

It was difficult even a few years ago to convince the I
mining engineers that so soft and resilient a material
as rubber could withstand the abrasive action of stone.
Such a supposition seemed unreasonable, but the test
of the actual use of rubber in comparison with metal,
leather, and other materials has demonstrated that
under this cutting and abrasive action it outwears by
several times any other substance. The rubber-sur-
face conveyor belt has come to be the most efficient
means of handling sharp-edged material. It carries
crashed stone, assists in unloading hot coke from coke-
ovens and in delivery to the cars, is used in loading

272 THE REIGN OP RUBBER

steamers with coal or stone, and handles ores of many
different kinds.

The service is rough and varied. Thomas Robins
writes in "The India Rubber World*' the story of a
belt salesman who offered his product to a quarry
superintendent with a guaranty that it would outwear
any other belt In the market. The superintendent took
the young man over to the plant where the big crusher
was at work turning out the two thousand long tons
an hour. Watching the empty belt, they stood at the
base of the huge machine. Suddenly the first loaded
car from the quarry dumped its thirty tons of rock
with a crash and a roar into the hopper that fed the
big crusher. The shock and thunder so frightened the
salesman that he ran away. After he had been
stopped, his first question to the superintendent was,
"Where was the accident?" He received the reply,
"That is an accident which happens one thousand
times in every twenty-four hours at this plant, and it
means that this belt which carries away the product of
the crusher has a practically continuous load of two
thousand long tons per hour, a large part of it in
pieces which you could n't lift."

Metal would wear out and be gone before rubber
would show serious evidences of wear under these con-
ditions. As a consequence, for purposes of carrying
trap-rock and limestone in stone-crushing plants, char-
coal and ashes in sugar refineries or in concentrating
plants and mines, earth and stone in large excavations,
blocks and logs of wood in pulp-mills, clay in brick-
yards, coal in breakers in connection with large power
plants and culm piles, tobacco in process of manufac-

BELTING, PACKING, AND HOSE 273 '

hire, cnstomers' packages in large retail stores, grain
in elevators, mixed goods in coffee-mills, phosphate
ore in the southern mines, chemical fertilizers in plants
all over the country, the cotton-rubber conveyor belt
is essential. For these uses and many others, it has
come into being and serves with a relatively low cost
of installation and a cost of maintenance that is un-
believably smaller than that of any other type of con-
veyors. Furthermore, it is quiet; and because it is
uniform in action, it is less wearing upon the motive-
power. More than twenty-two million dollars' worth
of belting was sold in this country in 1919.

Little out-of-the-way things, unheralded and unsung,
often serve large purposes. The youth who stopped the
leak in the dike was made famous — a rare accident.
The inventor of the steam engine, be he Hero or
Watt, found great difficulty, though, in sealing the
parts of it from leakage. In fact, in Watt's patent
of 1769 he states: "Lastly, instead of using water to
render the piston or other parts of the engine air or
steam-tight, I employ oils, wax, resinous bodies, fat of
animals, quicksilver and other metals in their fluid
state." Such packing between the cylinder and the
cylinder-head could not last long. Because boilers,
pipes, and engines need a little thing, — packing, — but
a stable one, rubber sheeting came to be used. Even
to lubricate and prevent steam leakage around the
piston-rods where they issue from the cylinder, stuffing
boxes in which packing is used are required. An
early engineering writer says, "The great desideratum
in a piston is that it shall admit of no leakage and
have as little friction as is consistent with this

THE BEIGN OF RUBBER

indepensable quality." Watt, the father of the steam
engine, tried to arrive at these results by the
use of a metallic packing, but with so little satisfac-
tion that he gave it up. A number of metal packings
patented in England before the middle of this centary
were displaced largely by vegetable and animal sub-
stances, specifically hemp and leather. Engineering
works of that period show accounts of pistons packed
with unspun hemp or long rope prepared for the pur-
pose, kept supplied with tallow by means of a fnnnnl
on the top of the cylinder lid.

The employment of cotton and fiber packing is of
comparatively recent date. Having engaged, however,
the ingenuity of some of the best inventors in rubber,
and possessing a fundamentally sound merit, the use of
rubber for this purpose has been steady and rapid in
its increase. The demand for packing has broadened
until that for piston rods is only one of the many kinds
produced. Most manufacturers make rubber-sheet
packing, in the form of cloth insertion and plain pack-
ing. The advantage In the use of rubber wherever
steam, air, or water joints are to be made is that no
other substance which has so much elasticity stands so
high a degree of heat. No satisfactory substitute can
be found where the iron surfaces of the joints are
rough or uneven. Rubber packing made with cloth in-
sertion is in wide use for steam joints, and the steady
increase in the yearly production is an evidence of its
value.

With the advent of superheated steam, there came
a demand for packing of special composition that
would render steam-tight the joints of pipe-lines where

BELTING, PACKING, AND HOSE 275

high-temperature and high-pressure steam is used. Al-
though rubber alone cannot serve here when the steam
temperature rises as high as 500 degrees, a combin-
ation of rubber and asbestos fibers gradually has taken
the place of all other sheet packings for use under
these conditions. Cotton, hemp, and flax do not pos-
sess great resisting qualities. Asbestos alone has not
the cohesion necessary, but a combination of rubber of
proper composition and asbestos as "superheat pack-
ing" serves well. This type of packing is, in reality,
a combination of hard rubber and asbestos — the as-
bestos to give strength and the rubber to give tight-
ness. Wherever steam is generated, rubber pack-
ing is found. Gaskets prevent leakage of air and
steam. Water pump valves go up and down millions
of times — some more than thirty millions before they
die and pass out.

Hose is the third of our trio. It is a family name
with many members: fire-hose, water hose, air-drill
hose, gasolene hose, radiator hose for automobiles, suc-
tion hose for fire-engines and for drawii^ water from
excavations, garden-hose, sand-blast hose, hose for
chemical fire-extinguishers. Of all sizes, these hose
vary from an inch long to five hundred feet. One
of this large family keeps trains running. Like the
axle-lighting belt, he lives in a poor place under the
end of a railroad-ear. He is married to one on the
next car to him, although an iron coupling is required
to keep the twain together. They are out in the
weather in a swirl of cinders or snow, bending and
creaking when the car swerves around sharp curves.
Serve they must at any time, at all times, for through

THE EEIGN OF KUBBEB

them passes the compressed air by which the brakes
are operated. We call them the air-brake hose. Al-
though only twenty-two inches long and one and three-
eighths inches in diameter, they are essential to the
successful operation of railroad-trains.

George Westinghouse probably made himself more
famous by his creation of the automatic air-brake,
patented in 1872, than by any other one of his many in-
ventions. The original non-automatic or straight air-
brake was based upon a very simple steam-actuated air-
pump on the side of the locomotive. Through the reser-
voir a pipe-line was carried the length of the train ; and
even in those days, the connection between the coaches
was by means of the hose and couplings. This appa-
ratus was inoperative in emergencies. Westinghouse
developed the automatic principle in such a way that
each vehicle carried its own source of power ; and by an
ingenious valve connection he caused the applicatiou
of the brake whenever there was a reduction of air-
pressure in the train pipe-line. This has gone through
numerous improvements and changes since the early
one; yet the rubber parts to seal properly the
air in the valve, and the air-brake hose, still constitute
essentials in this important factor of railroad trans-
portation. The quality of the hose has been developed
by cooperative action on the part of rubber manufac-
turers and the Master Car Builders' Association, so
that bursting hose is nowadays something almost never
heard of.

Several others of the hose family live in the dirt un-
der the car; they seem to like it. Safety in railroad
transportation depends heavily upon rubber. An air-

BELTING, PACKING, AND HOSE 277

'i^inal hose connects the coaches of a passenger-train^
and steam-heating hose carries exhaust steam from

the locomotive to radiators.

In every passenger coach there are six pieces of
hose, two of air-brake, two of air-signal, and two of
steam-heating hose. On the 2,500,000 freight-cars,
60,000 passenger coaches, and 10,000 Pullman cars, it
is probable that the air-brake hose equipment in the
United States includes a matter of 5,000,000 lengths.
Each of these is replaced about every six months or
year, because they cannot live long in an atmosphere
of water, snow, cinders, and dirt. About 10,000,000
pieces of air-brake hose are necessary every year.
End to end, these would stretch over 3500 miles —
enough to reach across the continent.

Air-brake hose is of uniform size, measuring one and
three-eighths inches in diameter and each piece being
twenty-two inches long. It is made of an inner tube,
several plies of strong, rubberized fabric, and an outer
rubber cover, all vulcanized together. After this
process, it is tested to make sure that each piece will
withstand the suddenly changing air-pressure of about
125 pounds to the square inch, the bending as the
trucks go around curves, and the deteriorating action
of the elements.

A sum of $26,998,000 was expended for rubber hose
of all kinds in 1919.

Were rubber to disappear, the price of copper, ce-
ment and coal would go up; for in mines delay and
added expenses would result. The rubber conveyor
belts, the hose to carry air to the drills that punch
holes in rock preparatory to blasting, the elevator belts

THE KEIQN OF RUBBER

that carry buckets loaded with acid Blimes ; these and
other rubber articles lead a rough life in the mines and
smelters. Dragged over rock, submerged iu water,
confined in an atmosphere of fumes, exposed to heat
and cold, none but the most rugged material can stand
the abuse ; yet rubber lives and works cheaply.

In every industry rubber works in diverse ways
and under varying conditions to serve mankind. The
paper of which this book is made was, when pulp, held
iu place by rubber deckle straps. It was pressed into
sheets by rubber-covered couch rolls.

But in the oil industry rubber is given its severest
test. Oil attacks rubber ; it is the chief enemy. Xhere-
fore the chemist has been obliged to mix with rubber
other substances and in this union to change ita
natnre.

From California to Oklahoma, from Ohio and Ken-
tucky to Pennsylvania, oil is pumped out of the ground,
delivered into tanks, passed through great pipe-lines,
and put on board ship for transport to other countries.
The big oil companies have tried all kinds of belts
for driving wells at high speed for twenty-four hours
a day, both by rotary chisels and percussion. By the
percussion method a 625-pound bit is lifted and
dropped into the hole ; in the boring method a one-hun-
dred-pound bit with a serrated tip is revolved at the
b,ottom of an eight-inch or ten-inch iron pipe. In
both these methods rubber belting is preferred, be-
cause it is tough, flexible, cohesive, and has greater
strength than belting made from any other substance.
It is water-proof, and it is more oil-proof than other
materials, although to make rubber oil-resisting is one

BELTING, PACKING, AND HOSE 279

of the most difficult problems faced by the rubber
chemist. Submitting to heavy, uneven shocks, rubber
belting has a durability that often extends as long as
five or six years, despite the oil and sand that come in
contact with it and the rongh and eareleaa usage to
which it is subjected.

In conveying oil, special grades of oil hose are uaed ;
and since these are dragged around a great deal, they
are frequently protected by metal armor consisting of
wire wrapped spirally about the length of hose. Some
of them carry water, some convey air ; but all of them
come more or less in contact with oil. For conducting
oil from tanks to barrels, the hose ordinarily has four
or five plies of frictioned duck, lined with an oil-resist-
ing rubber compound, and a closely-set, spiral, flat
wire extending through the core, not only to protect
the compound from possible corrosion but also to pre-
vent the hose from kinking or collapsing by reason of
the vacuum so often employed. To draw oil from stor-
age tanks of steamships or tank-cars, a suction and
discharge hose of exceptional strength is employed.
It must withstand the utmost extremes in weather, the
harshest handling, and continual contact with rapidly
moving oil.

Rnbber in the oil-field probably gets its severest test
in the pumps and the pump packings, which are of va-
rious sizes, kinds, and shapes. The foregoing enumer-
ation of rubber needs in oil-fields does not take into
account the many other articles that are quite indis-
pensable to handling oil from the time when the heavy
black fluid is drawn from the depths of the earth to the
time when, in the form of gasolene and lubricating

THE REIGN OF RUBBEE

oil, it 18 delivered to consumers — the tires on the
trnokB, the boots and the shoes, the gloves and the hats,
the rain-ooats used in sunshine as well as in rain.
Slopping about in sand and water, splashed with oil,
robber truly has a hard life in the oil-fields.

Of the four billion gallons of gasolene used by
motor-cars each year, all of it flows through rubber
hoee from the filling station to the tank in the car.
This is a specially made length of hose, the compo-
sition of which resists gasolene to the maximum.
Ilorv, if the manufactarer had not been alert, the
gasolene would swell the robber and disintegrate it;
suutkU pieces of rubber would pass into the tank of
the motor-car, eventually to clog the needle-valves of
the carburetor. By joint action between such insti-
tattons as the Underwriters* Laboratories in Chicago
and the Rubber Association, special constructions of
hose have been developed by which the amonnt of
action of gasolene upon the rabt»er has been reduced
to a minimum. This gasolene hose is usually made
with a ootton duck lining* and a helical Sat wire to
farther safeguard the mbber. Outside of this comes
rubber* tiim four plies of cotton fabric, and finally a
spindly ■vftrtmd layer of wire, usually covered by rub-
ber. Here again one finds flexibility, strength, and
resistukce to corrosion.

For those irtm go down to the sea in ships, be it in
OMUl-of-viir, Stthokariue. or passenger transport, rob-
In^r articles do va»ay thtn^. The first and the last
\v»>rk in which Charles Oo«xiyear was concerned had to
ilo with lifp-juvservers. Even now. though, rubber in
iH\unw>Uoa with Ufe-pre«erves is not used to the ei-

BELTING, PACKING, AND HOSE

of cork and cotton. It does not age well enong]
and air-bladders puncture. Life-preserving rubbi
suits would be more largely used were they
perishable. When the day oomes in which all rubber
articles are as permanent in the air and sunlight as
wood and steel, then the marked superiority of the
life-preserver made of rubber and fabric will be recog-
nized; and ship-owners will use such articles rather
than the somewhat more permanent but less adapt-
able cork belt. To provide greater safety in time of
need to the passengers, is a field in which shipping con-
cerns should interest themselves.

The diver depends for his life upon suits of rubber-
ized fabric, with heavy rubber gloves, with a metal
headpiece made water-tight by means of rubber gas-
kets, and, most important, with the hose that go down
from the pumps, to transmit fresh air and to remove
exhausted air. ,,

An ocean-going vessel is much like a small city;
every phase of human life and every convenience is
found there. Consequently, if we were to enumerate
the part which rubber plays in ocean or lake transpor-
tation, it wt)uld be necessary to catalogue the ways in
which rubber is used in the home, in the office, and in
the mill and the factory, with, however, the additional
requirement that on board ship, in the course of
storms, it is necessary to tighten aU openings to keep
the water out.

The numerous articles used in the mines, in facto-
ries, on railroads, and on board ship constitute, broadly
speaking, what the rubber manufacturer terms
^'mechanical rubber goods." Rubber products are

I
are M

282

THE REION OF RUBBER

grouped under the names of clothing, footwear, pneu-
matic tires, druggists' sundries, and mechanical rub-
ber goods. Mechanical rubber goods include a vast
number of products, large and small, the mere enu-
meration of which would fill volumes ; for there are
probably upwards of 20,000 to 40,000 different articles
in various sizes, shapes, and colors, and for myriads of
uses.

CHAPTER XVin
EUBBEE IN THE HOME

A comparison between the American bath-room and
the English one, reveals acme interesting differences.
In England one may not find a mbber hot-water bottle
hanging behind the door, but he is likely to find a stone
or metal one under the wash-basin. Of late years, the
English bath-room has achieved a rubber sponge, some-
times a solid rubber shaving-dish, and a rubber bath-
plug to keep the water from running out of the bath-
tub. In American homes, however, rubber has worked
its way into a large variety of convenient uses. The
hot-water bottle is one of the basic necessities. Then
there are fountain syringes, rubber bath-mats, rubber
soap-dishes, rubber aprons, rubber sponges, women's
bathing caps, the tooth-brush with its hard rubber to
keep the bristles from coming out, hand brushes, nail
brushes, shower attachments, and, in the spring when
colds are prevalent, the rubber bulb and tube connected
to the nasal spray outfit. We surely depend upon rub-
ber in the American bath-room and medicine-cabinet.

The American loves his bath-room, whether it has
tub or shower. But he does not want the water to run
all the time. It leaks too much from bib and faucet
as it is. By a soft rubber disk pressing against metal
when the wheel is turned, the water is shut off. If our
plumbers would use high-grade rubber mixtures

tures for ^H

THE REIGN OF EUBBER

these disks, there would be less trouble in the hoaae-
hold ; too many of them contain no rubber at all, being i
merely paper, which soaks up water and wears out
rapidly.

I am afraid this chapter will read too much like an
advertising man's copy, with rubber, rubber every-
where. But we do live in the reign of a rubber de-
mocracy in which there are many members. Not the j
least of them is the gentle lord of the bath — the rubber I
sponge. Purity and cleanliness characterize this in- I
timate individual. Usually, it is formed of a large
proportion of rubber, with considerable oil to make it
soft and flexible. With this is mixed sulphur in the
finest form. To attain such fineness the sulphur is
made by chemical precipitation with the vulcanizing
ingredient, antimony sulphide, a mild accelerator. In-
corporated with these is some substance like ammo-
nium carbonate, which, upon heating, produces a gas.
This rubber mixture is not mixed in the usual way,
but so as to be soft and uniform. Unless plasticity
is attained, the rubber will not "blow," as we say-
After pieces of the mixture are put inside hollow iron
molds, heat is applied only at the temperature at which
gas is given off from ammonium carbonate. The soft
plastic mixture, by reason of the gas, rises like bread,
blowing up into bubbles with little membranes of rub-
ber between them. Finally, as the process goes on, the
entire cavity of the mold is filled with the porous mass.
The heat is then increased up to the vulcanizing tem-
perature, and kept there until the rubber is completely
vulcanized. After cooling the mold is opened, and the
sponge, in somewhat rough form, is removed. By a

ISM aur

RUBBER IN THE HOME

atmple device the outside skin is cut off, and the sponge
as we buy it in the drug store is ready.

But the flowers, garden, and lawn need their shower-
baths as much as do we, to keep^ their vitality during
the summer's heat. Rubber garden-hose is their true
friend. Out on the golf course night after night a
little twinkling light may be seen, flitting from green
to green. The spooks might be playing golf, but
it is not they, nor is a duffer player practicing putts.
Most of us putt in the dark on Saturday afternoons.
No, in this case the greens man waters his greens by
night with length after length of rubber garden-hose
to convey the water needed for the growth of the deli-
cate bent and fescue grasses. Players are exacting;
each square inch of green must needs be covered evenly
with fine blades of special grass. We cannot drag
iron pipe over greens to tear and roughen them.
Thus, rubber garden-bose serves the golfer as well
as the gardener. Probably two thou.sand miles of
garden-hose are made in the United States every
month.

Garden-hose is constructed of several essential
parts : an inner tube heavy enough and uniform enough
to retain water and not to deteriorate on standing; a
cotton fabric or cord body of several plies, between
each pair of which is a rubber layer to stick the cotton
together ; finally, an outside rubber cover, thick enough
to withstand tearing as the hose is pulled over the lawn
and the sidewalks. It is probably the one article that is
handled by the user with the least consideration. Who
of us picks it up carefully and carries it out to the
front lawnT We grab one end and drag it. We kink

THE REIGN OF RUBBER

it in several places; we haul it over the sidewalt; we
jerk it and pull it if the coupling happens to catch. We
give it every possible abuse. It is out in the weather
constantly; and when the cover or tube is punctured,
the fabric decays in contact with water.

The rubber mixtures for tube, insulation, or cover —
and they do not differ greatly in composition — are
taken after mixing into the hose manufacturing depart-
ment. Here the first operation is to form the tube of
the hose by squeezing the compound through the die of
a tubing machine, as previously described. Before the
rubber is fed into the tubing-machine, an operator
softens the compound, or, as he calls it, the "stock."
He then cuts it into strips and passes it to another
man, who operates the machine. The second operator
feeds this warm, soft stock into the cylinder at the feed
end, another man watching the issuance of the long,
hollow tube and seeing that it is carefully wound up
upon a large reel or drum. The composition must be
stiff enough not to collapse; and to prevent its sticking
together in any place, a little soapstone is fed into it
through a special attachment in the die. Mean-
while, a slight air pressure is maintained inside
this tube to keep it in shape. When about five
hundred feet of it are wound upon the reel, it is rolled
to the braiding-machine. After the tube is rounded out
by just enough air-pressure to give it shape, it is au-
tomatically fed to the center of the braiding-machine.
This is a noisy instrument, like all cotton machinery.
Little spools containing cotton cord are forced by the
mechanism in and out and around each other in such
a way that, as the rubber tube passes up through the

RUBBER IN THE HOME

macliine, it is surrounded by interbraided cotton cords
spirally and continuously woven.

Some garden-hose is made on the plan of the cotton,
mbber-Iined fire-hose, but in the type we are describ-
ing one ply or layer of cotton cord ia not sufficient to
give strength and durability ; therefore, when this reel
of unvulcanized hose is covered with its layer of cord,
it is taken back to the tubing-machine again. But how
shall a partly made hose be covered with rubberf We
certainly cannot pass the hose through the cylinder of
the machine and through a die, for that would simply
grind it up, cotton and all. Here a leaf is taken out
of the book of the insulated wire manufacturers.
Upon this particular tubing-machine is an insulating
head; that is, a piece of metal with holes properly
arranged in it is so placed on the head of the tubing-
machine that the entire hose may pass through a cav-
ity running at right angles to the direction of the flow
of the rubber. As the hose passes through this cavity,
the tubing-machine forces soft, unvulcanized rubber
around it. By an ingenious device the die of this in-
sulating head permits only a certain thickness of rub-
ber in the form of a continuous tube to be laid on the
surface of the cotton. Thus, our rubber hose now
issues from this operation with a thin layer of rubber
on top of the cotton layer. After the reel is filled again
with five hundred feet or more of insulated hose, it is
taken back to the braiding-machine. Once more the
little spools run around each other, and a second ply or
layer of cotton cord is wound upon the partly manu-
factured hose.

Still the hose is not complete ; for certain uses, three

288 THE EEIGN OF EUBBEE '

or even four plies of cord are necessary. We shall
assume, however, that three plies are required. The
hose, after the application of its second layer of cord,
goes back to the insulating head of the tubing-machine,
through which it again passes and adds another layer
of rubber. Then back it goes to the braiding-machine,
where the third layer of interlocked, woven cotton cord
is applied. So far as strength is concerned, we should
need to add no more rubber to this hose, with its tube,
its three plies of cotton, and its two layers of rubber
between them. But we know that it will be dragged
about on the ground and in the water; we know also
that water causes deterioration of cotton, for wet cot-
ton mildews and decays rapidly. Therefore a protect-
ing layer of rubber must be applied outside this last
layer of cotton. Back again goes the almost completed
hose to the tubing-machine, .whe^e it passes through
the insulating head and die. In 'this case, however,
there is applied a somewhat thicker layer of rubber
of a different mixture, a tougher one, designed to re-
sist the wear and tear on the ground.

These operations have produced five hundred feet
of garden-hose, blown up with a few pounds of air-
pressure to keep it fully rounded. Wound up on a
reel, the layers separated by paper or varnished cloth,
the hose, on a factory type of small wheel truck, is
pushed into another room. Here several of these reels
are gathered together at one end of a long vulcanizing
press, for the hose is to be vulcanized at the rate of
about twenty feet at a time. To accomplish this, two
heavy steel plates have been made, each of them

HI ^ n. * S

t'm ""■■ "—

^Mm

'" '^ Nil

I grooved ful

RUBBER IN THE HOME

289

grooved full length. When these two plates are
brought together, there is a circular opening through
their length of the exact diameter desired as the out-
side diameter of the hose. One of these plates is
holted to the top of the press, and the other is bolted
to the movable part. Each plate contains six to ten
of these semicircular grooves. The operator draws
into the grooves a length of hose from different reels
sufficient to fill them from end to end. Then the lower
half is pushed np by hydraulic pressure against the up-
per half, thereby confining the hose in the tubular open-
ings formed by bringing together the two sets of
grooves. The hose is in contact with the hot plates or
molds long enough to vulcanize the composition. The
plates are then separated, and the hose is pulled
through to bring another length in contact with the
mold. Again the molds are closed and heated. Thus,
twenty feet or more at a time, the hose is vulcanized
from end to end. When it is inspected and the rough
ends cut off, finally it is rolled upon a wooden packing
reel, ready for shipment. There are other methods of
making garden-hose, but this is probably the simplest
of them all.

There are many different kinds of hose, not the least
important of which is that for conducting solutions of
chemicals used in spraying orchards. Fruit would be
poor indeed were insects not killed by chemicals applied
by orchard sprayers, with their rubber hose connec-
tions of special sizes, lengths, and types. The little
hncket-spray pumps with four- or five-foot lengths
of three-eighths-inch spray hose, the large horse-drawn,

THE REIGN OF BUBBEE

and the gasolene-power types, all have hose connecting
them and permitting the operator to move about and
thoroughly spray his orchard. Sprayers of the power
type usually develop pressure from 250 to 300 pounds
to the square inch. The fabric construction of the
Bpray hose must be made to withstand these preasureB.
Furthermore, since spraying liquids are composed of
different chemicals, the lining of this spray hose must
be made of most carefully constructed rubber mixture.
The problem is not wholly one of pure rubber; it is
a question of mixing with pure rubber those ingredi-
ents which give toughness and strength to the composi-
tion, and an ability to withstand the action of the chem-
icals. This condition is somewhat difficult to attain in
rubber, particularly when emulsion sprays containing
oil are used. Rubber absorbs oils with great rapidity;
it swells, softens, weaJtens, and deteriorates under
their action. Therefore, he who sprays his orchards
would be wise if, after each operation, he were to pass
through the hose a sufficient quantity of water to wash
out the chemicals and thus minimize the action of them
in the deterioration of the rubber.

Another of the necessary uses of rubber in modem
days is in the home canning of fruits and vegetables.
"We think of the process as new, but in 1795 a method
was invented by a Frenchman, Appert, for preserving
foods in hermetically sealed receptacles. He was
awarded a prize of sixteen thousand francs by the
French Government. His process consisted in placing
the articles to be preserved in cork receptacles and
subjecting them to the heat of boiling water for various
lengths of time, depending upon the nature of the
foods. Although Appert 's process was kept secret for

RUBBER IN THE HOME

291

some time, it gradually leaked out; in 1815 it was
brought from England to America. In 1819 an Eng-
lishman named Daggett had a canning factory in New
York City for packing lobsters, salmon, and oysters;
and in 1825 fruits and vegetables were canned. At
this time only glass jars were used ; but the cost and
frequent breakage led to the use of tins, the first pat-
ents for which were secured in England in 1823 and in
America in 1825. Because sterilization by boiling in
water was found to be insufficient for many products,
salt was added to the water to raise the boiling-point.
In 1874 a Baltimore man invented a closed retort for
cooking with superheated steam. From this came
our modern steam-pressure devices, which produce
various temperatures above 212° Fahrenheit.

The canning industry has become extensive. The
figures amaze one. The National Canners' Associa-
tion reports that in 1919 there were packed in the
United States more than 1,385,000,000 cans of vege-
tables, more than 634,000,000 cans of fruits, and more
than 716,000,000 cans of fish and oysters. These make
a total of more than 2,736,000,000 cans "put up" in
one year. And the home is not heard from in these
records.

Without entering into the principles of hot canning,
we should note one fact as fundamental ; the cans must
so be sealed as to prevent any ingress of air. Among
the many substances used for this purpose, the chief
of them is rubber; even the tin can usually has a little
rubber seal between the sides and the base. Because
it is odorless and tasteless, because it is resistant to
the action of fruit acids, because bacteria cannot grow

392 THE REIGN OF BTTBBEB

in it, rubber has become one of the most neceseary
links in this chain of important operations, the end of
wliich is the preservation of food in palatable, health-
ful, uyable coudition. Before canning, all the fruits
and vt?«:etables are picked over in the factory, jast as
our tfooks do in the kitchen. Girls with carefully ster-
ilized and manicured hands sit before a long table upon
which slowly moves a sanitary rubber conveyor belt,
mtuttily white in color, which carries the fruit to be
aofted.

tu th« home, large quantities of fruit and vegetables
U* prv»erved each year in glass jars. This process
te more economical than the use of tin, because the jars
oau be used repeatedly. The glass top, however, must
be air-tight; and for this purpose, ever since home
Dunning began, the rubber ring, known generally aa
the "jar ring," has been used. The jar ring is busily
engaged in filling its mission in the twenty-four mil-
lion homes in our country during the canning season.
One rubber company alone informs me that it makes
every hour during the winter enough rubber jar rings
of one brand alone to make a pile, one on another, as
high as the Woolworth Building; and their prodnction
for a year of this particular brand would, if linked in
(he form of a chain, go around the world three times.

h\ the process of making jar rings the first essential
Ih the choice of a rubber composition. This compoai-
Hiui luuMt have certain properties: it may contain no
•tilbMiHUcei* that can be absorbed into the acid liquids
•litd ijlve either taste, odor, or poison to the preserves.
M'itH' it i** mixed in the usual way this rubber com-
iniiiiid U umnur«otured by a very simple process, h

RUBBER IN THE HOME 293

is taken from the central mixing-room to the jar ring
factory, where it is warmed on a warming-mill and
forced through a large die in the head of a tubing-ma-
chine, much in the same fashion as garden-hose. Gar-
den-hose tubes are small, but the tube from which the
jar ring is cut is large in size and thick in wall. The
thickness of the wall is that of the width of the thin
section of the ring as the consumer obtains it.

As the tube comes from the machine, it is cut into
short pieces, usually about three feet long. An opera-
tor places the tube upon a mandrel or iron pipe. Then
a large number of these mandrels are put into a vul-
canizer containing water; and the vulcanizing is done
by heating this water to the proper temperature and
maintaining in the water, usually, a slow but regular
circulation. When this heavy tube is vulcanized, it is
removed to a jar ring cutting machine. Here the
workman has but to remove the tube from the mandrel
and place it upon a cutting mandrel, and the machine
does the rest; that is to say, a sharp knife runs in and
out, cutting the rings automatically at the rate of fifty
thousand an hour. After they are cut, they are care-
fully inspected by expert girls, counted, and packed in
the boxes in which they are sold,

As I write, the canning season in my home has just
begun. Strawberries are coming in from the garden;
soon it will be currants, raspberries, and later, peaches.
For several weeks the kitchen will be redolent
of sweet smells, but mere man must stay out of the
bustle and boiling. Whether hot pack or cold is being
used, as a rubber man, I look after the jar ring pur-
chases, to see that they are of proper quality. I de-

THE EEIGN OF RUBBER

mand good quality ; the rings must be strong enough to
stretch around the top of a Mason jar and not so soft
that they will squeeze out and leave places for air and
fungi to creep in and spoil the fruit, if I am to par-
chase them.

All rubber men lite fruit in the winter, I imagine.
Perhaps for this reason, as well as from a sense of
responaibility for the needs of the householder, they
got together some years ago and, with the cooperation
of the Bureau of Standards, developed for the Depart-
ment of Agriculture, that loyal agent of the house-
wife, a specification according to which jar rings
should be made. Responsible manufacturers take
pains to see that these specifications are carried out.
It is simple for you to test jar rings in accordance with
the Farmers' Bulletin No. 1211 of the United States
Department of Agriculture, "The Home Canning of
Fruits and Vegetables." The tests, if followed,
will show you whether the jar ring will feustain
a load of seventeen pounds before breaking, and
whether it is flexible enough to stretch from four inches
up to ten inches without breaking. These two tests
of strength and stretch are the fundamental ones
Indicating a good rubber composition. For use
in the hot pack method it is advisable to test the ring
in boiling water. In position on a jar and placed
in boiling water for four hours, it should not,
after cooling, be swollen or show signs of cracks or
cute resulting from pressure.

If your home happens to be on the farm, you prob-
ably sell milk. The old-fashioned method of milking
by hand is gradually giving way in the larger dairies

RUBBER IN THE HOME

to newer methods of milking by machinery. Conserva-
tive as we may be, and desirous of holding to the old
and not taking on the new, yet demands for sterile,
clean milk have grown to be so heavy that every pos-
sible method to prevent contamination by dirt or t
teria must be adopted. Therefore the milking-ma-
chine is coming more and more into use.

There are many different types of milking-machines.
The experimental work leading to their development
began probably as far back as 1819, but modern de-
velopment began about 1878. There have been three
different principles. The milk-tube idea, providing
for an opening into the milk cistern and allowing the
milk to flow from the udder, is dangerous and is not
used. The second method adopted the pressure prin-
ciple. The third method, which has come into extensive
use, places the teat into cups from which the air is ex-
hausted, the exhaustion producing a vacuum in the
manner produced by a calf when suckling. There have
been different patents, but the fundamental principle
consists of a vacuum pump or "pulsator," To this
pulsator are attached two lengths of rubber hose and
a specially designed connection for teat cups and teat-
cup mouthpieces. Thus a pulsating vacuum is ap-
plied to the teat, bringing its flow of milk into the vac-
uum milk-pail.

The particular rubber parts which make this milk-
ing-machine possible are the teat cups, the rubber
tubes that convey the milk into the pails, and the rub-
ber hose that permits a vacuum to be applied to the
milk-collecting pails. These cups are made of purest
rubber, soft, flesible, and permanent.

296 THE BEIQN OP BUBBEB

All things that come in contact with milk ^Bot be
kept clean. To enjoy good milk, one mast heep the n^
ber partH just b9 clean and sterile as the paOs aBdcaao.
Those who nse miUctng-machinery shooM be careful
to see that the directions of the mUking-miiidnaf com-
panics are carried oat. The mbber parts sboald be
washed and carefully sterilized ; and between the
that the machine is used, they should be kept i
in plain boiled water. The rubber tubing and enpa
should never be allowed to become dry. To steiifixe
them, the College of Agriculture at ComeD Um-
vereity recommends a solution of water containing
salt and chloride of lime. It is well to remember thai
the fatH of milk are readily absorbed by mbber; if,
therefore, the rubber parts are not washed after each
milking and kept in sterilized water, more and more
butter fat will be absorbed into the mbber, with conse-
quent deterioration. The secret of keeping the rubber-
ware sweet is always to store it wet with clean water
and never to let it come in contact with oils or fats, for
they swell and weaken rubber.

Within the limits of our space, all the articles of mb-
ber found in the home could scarcely be described.
They are too numerous, although different enoagh to
warrant separate treatment. For comfort on cold
nights milliouH of hot-water bottles are in use. They
are made from sheeted rubber, colored, adorned with
configurations on the surface, to be agreeable in ap-
pearance. Girls build them into shape, or men mold
them in steel molds under pressure. Only the clean-
est rubber and the most dirt-free processes are
ployed, for the bottle must not leak.

RUBBER IN THE HOME 297

Even straw and felt hats, awaiting the call to adorn
the head, have been helped by rubber forms upon which
they were pressed in the making, and in so intimate
an article as the garter and the "braces" of the Eng-
j lishman we depend upon rubber thread, while rub-
I her has come to replace leather in the belts preferred
by American men.

But it is in relief from the burdens of housework
that rubber serves as a real aid to the housewife, in
city or country. Sweeping and dusting are made easier
by rubber-wired and rubber-tired vacuum and carpet
Bweepers. To the sewing-machine electricity is con-
ducted by rubber-covered wire. But best of all is
the routing of blue Monday wash-day. The laundry
in recent years has changed from a back-breaking
place, dreaded each week, to a light, happy room.
Equipped with motor-driven washing-machine and rub-
ber wringer rolls, with soft, warm rubber mats and
with electrically heated mangle, this part of the home
has become a scene of happiness.

Rubber in the home is a dependable commodity. It
is gentle, noiseless, — a good servant.

CHAPTER XIX

GAS-MASKS

One fine afternoon in May, 1917, a telegram came to
my office from Washington, which stated that Profes-
sor Gibbs of the Bureau of Mines would come to see
me on an important matter connected with the war.
The following morning he arrived and showed me a
gas-mask of the box-respirator type that had been
made by the English. He asked if it could be dupli-
cated easUy. There was very little gas-mask infor-
mation in the United States at that time. The first
mask brought to this country from the front was of
German make. This type seemed to fit the needs of
the Navy Department, and a small order had been
placed with the robber companies. After the usual
difficulties incident to a new article, we had duplicated
the German construction as closely as possible. Little
was known over here at that time of the type of chem-
icals used for gases; else I am sure a considerably
different type of rubber material would have been em-
ployed in making these first gas masks.

On Wednesday of that week, Bradley Dewey came
into my office, after having been heralded in advance
by a telegram from Washington. His first remarks
were, as always, straight to the point. "We want
you," he said, "to make the rubber parts for 25,000

GAS-MASKS 299'

gas masks by ten days from to-day." He was notlimg
if not direct. We told him that he might as well ask
us to move the building in which we were sitting to
Brooklyn in ten days. Such a retort made no impres-
sion; he went right on: "I am not yet commissioned;
I have no formal order to give you. You will have to
run your chances of getting your money back ; but we
want the masks, and we are going to have them." He
gave no reasons for his statements; but we sensed one
and thought at ouce, as it subsequently developed, that
probably a force of American soldiers was to go over-
seas immediately and needed full equipment. It was
of no special credit to the B. F. Goodrich Co., that we
accepted the call. All American business men did the
same in those days.

Because of the method of design, it would have been
impossible to create an exact duplicate of the English
mask in so short a time. Short cuts, modifications to
permit speed of production, were necessary. The
technical staif, officials, and Bradley Dewey sat down
together and worked out the program. By Saturday
there were thirteen machine-shops making the metal
forms and molds. They jumped in to help, as did
thousands of little shops in this country, whose names
are unknown but which were keystones in the ajchee
of the war machine. By Monday the regular peace-
time occupations of two departments of the factory had
been abandoned, and in place of them various gas-mask
parts were in process of manufacture. By Wednesday
we were making more than three thousand masks a
day ; and at the end of the ten days we had nearly com-
pleted the order. These were not good masks; but

THE REIGN OF EUBBER

they did have a definite value in offering some pro-
tection against gas.

More than all else, however, this initial attempt
taught us many things regarding the size and details
of the gas defense problem. As Crowell and Wilson
say in their "Armies of Industry": "To produce
25,000 gas-masks in three weeks meant to compress
England's two years of experience into twenty-one
days. The military authorities at that time could
plead entire ignorance of the qualifications of an effi-
cient gas-mask. The prevailing idea seemed to be that
you could go out into the market and buy them by
the hundreds of thousands as you could buy Hallowe'en
masks."

More information filtering through to us from
abroad during June, we came to realize — ^manufac-
turers, and War Department — that this was no ordi-
ary war and that protection against the highly com-
plex and constantly changed poisonous gases was a
matter that would require research work of the first
magnitude and cooperation of the highest degree.
For this purpose the Gas Defense Division of the
War Service Committee of the Rubber Association
was organized to coordinate with the Wax Department.
To their lasting credit, be it said that always the army
officers were pleasant, courteous, progressive, and fair.
The committee and the officers together wrote specifi-
cations according to which the manufacturers produced
the masks. They made them severe in order to insure
to the soldier a resistant, durable protection.

To comprehend gas-masks, one should understand a
little of gas warfare. Gas is the most treacherous

GAS-MASKS 3011

of all the weapons of offense, for it may be somethingi
like the ancient Greek, Pelopidaa, who, so Plutarch I
states, on hearing the remark of a soldier, "We are |
fallen among enemies," replied, "How are we fallen
among them more than they among us?" In its use,
the wind may change and blow the gas back to the
place whence it was sent. Poison gases were first used
in warfare between 431 and 404 b. c, when the Athe-
nians and Spartans, in the southern part of Greece,
besieged certain cities. In doing this, they tried to
overcome their opponents by the use of burning sul-
phur, which produced fumes irritating to the eyes and
throat. While we may look back to ancient Greece
with awe and admiration for wonders of art and liter-
ature, we must give them the discredit of having insti- ^^
gated the use of chemicals in the attempt to outdo W^
their enemies. ^H

Despite international prohibitions, Germany had
planned the use of noxious chemicals before the war
broke out. Ludendorff states in his "War Memories"
that the Germans used gas shells against the Russians
on January 31, 1915. Gourko, the Russian, writes
that at about the end of December, 1914, the Germans ^^
introduced shells charged with asphyxiating gases. ^^

Regardless of these early preparations of the Qer- ^|
mans, the English and French were taken completely ^^
by surprise in April, 1915. Because something had to
be done and quickly, Lord Kitchener appealed to the
women of England, by whom the first mask was made, ^H
which was not a mask at all. It was merely a series ^^M
of cheese-cloth pads soaked in chemicals. ^H

j^L The French studied protective devices. The first ^H

THE REIGN OF RUBBER

flat pieces of rubber vulcanized together on the edges.
When air was breathed out of it, it opened easily; but
it shut itself tight at each inhalation.

The face-piece of the English box respirator was
made of a thin cotton fabric dyed olive drab, upon
which was applied a smooth layer of rubber vulcan-
ized in hot air. It was secured upon the head
by means of tape and elastic bands. In order
that there might be no breathing through the nose, a
nose-clip with rubber ends was used, the force of wire
springs keeping the nose shut. The breathing, there-
fore, was done through the mouth, into which fitted
a special mouthpiece of rubber upon which the teeth
could close. A rubber flange that lay between the
teeth and the lips prevented the soldier from breathing
any bad air that might be inside the face-piece, when
he opened his lips under severe exertion. This ar-
rangement gave to the mask what was called the double
line of protection.

There were serious objections to the mask. Per-
spiration from the face rapidly condensed upon the
eye-pieces, so that vision was seriously interfered
with. The nose-clip, the mouthpiece, and the lack of
ventilation within the face-piece chamber produced ex-
treme discomfort.

To overcome these difficulties, particularly that of
the fogging of the eye-piece, Dr. Tissot, a Frenchman,
in 1916 invented a mask that consisted of a metal bos
carried on the back, containing the absorbent mate-
rials, through the lower part of which the air came
in, and out of the upper part of which the flexible tube
passed over the shoulder to the mask inlet. The face-

GAS-MASKS 305

piece was made of almost pure gum rubber. To
avoid the dimming of the eye-pieceB, little tubes were
run up to them from the inlet, so that all the air
breathed in was swept over the inside of the eye-pieces,
and prevented moisture from condensing upon them.
This Tissot mask was used for artillerymen, observers,
and sappers. W-hen it first came to America, the idea
stimulated development for the infantry. Because
the face-piece was tight and comfortable, because the
eye-pieces did not become dimmed, because there was
nothing in the soldier's mouth to prevent his talking
and to compel salivation, this mask was more comfort-
able than any previously developed apparatus. The
rubber was thin and of great flexibility, but lacked
durability.

To perfect such a comfortable mask required con-
stant tests and studies. It had to fit the face perfectly,
leakage around the edges having been observed in
testing-chambers built for that purpose by the Chem-
ical Warfare Service. By going into these chambers
in the presence of diiTerent gases and under different
concentrations men tested leakage. The ' ' poison
squads" were always at work. The physiologists and
the psychologists studied the best shape of masks. It
was necessary for thetfi to fit into the hollows of the
temples and give the jaws free space in which to work,
yet not press back against the Adam's apple. The
early masks were a joy to the fat man, but a terror to
one with a cavernous face. With the pressure of the
mask on the forehead carefully determined, the line
of pull of the attaching bands was regulated so that
pressure upon the supra-orbital nerves, just above the

THE REIGN OF EUBBEE

eyebrows, became so small that the discomfort from
it was reduced to a minimum.

To fit all sizes of faces and heads was a problem.
Equipped with regular as well as experimental maslcB,
men of the Field Testing Section of the Gas Defense
Division were constantly in and out of gas. They
played base-ball in masks, dug trenches, laid out wire,
cut wire, and fought sham battles at night, both with
and without actual gas. Without ill effects, men
worked, played, and slept in the masks for a week at
a time, only taJiing them off for thirty minutes to eat,
and each day entering high concentrations of deadly
gases.

The dream of the gas-mask designer was to create
one that could be worn constantly, and to this end
the greatest efforts of rubber men and army officers
were devoted. The first step toward this ideal
was a modification of the French Tissot, which came to
be known as the AT or Akron- Tissot mask. The face-
piece was made of the cloth known as stockinette, un-
der which was a layer of rubber, the whole being vul-
canized on a form the size and shape of the face. An
attempt to build a mask to fit a face, just as a rubber
shoe is built to fit a foot, was made by cooperation
between the Chemical Warfare Service and the Rub-
ber Association. In order to keep the eye-pieces
free from moisture, a specially formed rubber tube was
made to fit upon a peculiar, snout-shaped, metal nose-
piece. This rubber tube was of a Y-shape, laid inside
the mask, in distinction from the French Tissot.
Therefore, the incoming air went through these tubea

GAS-MASKS

307

and swept over the eye-pieces. Cotton webbing con-
taining rubber thread was attached at the proper
places to hold the face-piece in contact with the head.
Although still not quite thick enough to withstand
gases for the maximum time, these masks gave an
excellent account of themselves. Another type was
known as the KT mask.

I have made little mention of the other rubber parts
of the mask. The face-piece, the flutter-valve, the
head-bands, and the flexible hose all are made of rub-
ber to a greater or less degree. There is also a neces-
sary little rubber valve, about which no one has said
much, on the inlet side of the canister. This valve
has the duty of closing on exhalation and opening on
inhalation, so that it acts exactly in the reverse way
from the flutter-valve. If it ever fails to act, some
of the air passes back through the canister and de-
creases the absorbing power of the chemicals.

At Long Island City was built a large gas-mask fac-
tory with technical laboratories where ideas were
worked out in a spirit of cooperation and earnestness
to produce the best possible gas defense equipment for
the American soldier. The speed with which the or-
ganization was brought together and harmonized and
production accomplished will ever stand as a monu-
ment to the Chemical Warfare Service. It brought
together and combined the ideas of those who had been
overseas and those connected with rubber, with the
result of field tests. Cooperation was the watchword,
a real part of which was with the liaison officers from
England and France. Those who came to know Major

THE REIGN OF RUBBER

shells; and in May, during the German preparation
for attack on the Aisne, the artillery programs con-
tained as much as 80 per cent, of gas shells for cer-
tain objectives. Chemical warfare really includes in-
cendiaries, smokes, and gases. The aeroplane and
the dirigible on both sides used incendiary bombs, as
well as gas shells. Which is worse, to be suffocated by
the smoke of burning buildings, or put out of action
by phosgene or chloracetophenone f All war is pain-
ful and dangerous. We naturally think in terms of
personal experience.

When chemistry becomes better understood, we
shall be free from the idea of the mystery of it ; and
the pain and suffering from these numerous types of
gas will be found, in point of fact, to be less than
that from shrapnel and projectiles. The horrors of
gas have been preached from press and pulpits. Yet
facts do count; and when the Surgeon-General tells
us that the man who was injured by gas alone on the
field of battle has twelve times as many chances for
recovery as the man wounded with bullets and high ex-
plosives, we must be impressed. Likewise, bullets,
high explosives, and other methods of warfare than
gas, were responsible for twenty-five times as many
blinded men; and, in addition, the explosives caused
losses of legs and arms to an extent that gas could
not and did not do. Even tuberculosis was really less
frequent among those gassed than among those who
enlisted and were not gassed. It would seem apparent
that the evidence is rather in favor of the humanity
of gas warfare. This attitude is not the thoughtless
one of propagandists ; but it is really the cold, definite

GAS-MASKS

311

conclusion of technical men who have nothing to gain
by making such statements other than the satisfac-
tion of speaking truth to those who would read it.

General Fries well states: "As between the mask
and poisonous gases, we have the old struggle of the
battleship armor against the armor-piercing projec-
tile. While the armor-piercing projectile has always
had a little the better of the game, it is jnst the re-
verse with gases." Nevertheless, protection in the
form of further development is a vital national need-
New chemicals will continue to be made; it is easy
to manufacture them secretly, test them, and get ready
for any war which might come. Those of us who are
in chemical industry are inclined to believe that all
the treaties that may be signed will not eliminate
danger from the gas attack. As long as the possibil-
ity of war continues, we shall have a problem of de-
fense which should be met by research work on all de-
fensive appliances. If gas-masks can be made having
perfect resistance in the face-piece, a high degree of
gas absorption in the canister, availability through
ease of manufacture, comfort in inhalation and ex-
halation, and a glove-like, easy fit upon the head, that
nation which can produce such protective appliances
will at least, be in the strongest defensive position.

Research of this character is of vital importance to
this country, and cooperation to that end should be
sought; for the world's history shows that no weapon
of offense has ever been discarded.

The captive balloon has been called the eye of the
artillery. With this balloon five thousand feet in the
air, swaying at the end of a long steel cable, the ob-
server sat in his basket. He was truly, in the World
War, the chief means by which fire from the camoii-
fiaged batteries came to be accurately placed. The
World War was one based on mathematical science,
for the barrage and the exact placement of shells were
factors which, in no small degree, were responsible
for the holding of the lines on the Western Front.
No concealment was possible for this observer; he
was held aloft by hydrogen retained in a rubberized
fabric bag of peculiar design. His telephone wires,
insulated by vulcanized rubber, went down through
the center of the steel cable. Dependent he was,
therefore, in more ways than one upon rubber for the
success of his work. It was no easy job. Although
he floated over a beautiful country, yet the landscape
was not his to view, except in the particular spots
where shells struck and burst. Many perils were
his; the rapidly moving aeroplanes from the enemy's
line were peculiarly enemies, for they were specially
eonmiissioned to hunt down captive balloons and set
them on fire with incendiary bullets. The balloon

BALLOONS

313

was the target both of long-range gune and of air-
craft.

It has been stated that the average life of a kite-
balloon on an active sector of the Western Front was
estimated to be abont fifteen days. Some of them
lived only a few minutes, and the War Department
reports that only one American balloon passed un-
scathed during the whole period of American activity
on a busy sector. It is interesting to the rubber man
also to read the reports that show how five or sis
months of non-war service will deteriorate the balloon
fabric; although there are many instances of usefal
service longer than this. A dangerous business is
this ballooning, but a- vital one. To the humble ob-
servation balloon goes much of the credit for the
marvelous accuracy attained by artillery during the
war.

Balloons have been known for many years. The
Montgoliier brothers, Frenchmen, in November, 1782,
made a paper-bag balloon. When filled with hot air,
this was large enough and buoyant enough to permit
them to send up a sheep, a rooster, and a duck.

I remember well how, as a boy, ballooning attracted
me, after a visit of Captain Baldwin to the County Fair
in the small town where I was brought up. I suppose
most small boys have seen the balloon and the para-
ehute-jump made by these early spectacular perform-
ers, who entertained the multitudes by ascending in
spherical balloons and jumping from them. Then it
was simple for us to study how balloons were
With light-weight paper, scissors, and paste, it
easy to lay out the parts in the barn and to construct

hen it ^^M

made. ^^M

was ^^M

struct ^H

314 THE KEIGN OF RUBBER

the panels and gores for making balloons larger than
could be bought from the fireworks store. We sent
them np with hot air generated from a wood fire, with
a piece of tile as a chimney and a concentrator; and
night after night, during the summer, when the air
was clear, these little balloons have floated above the
country, dropping parachutes with Japanese lanterns
in them, scaring the timid with fear of fire, but stimu-
lating in the soul of American youth that future love
of the air which was to develop so rapidly and so suc-
cessfully during the war. We but repeated in a small
way the Montgolfier brothers' exploit.

A little later, after the brothers had performed their
feat, two other Frenchmen, De Eozier and De Vilette,
ascended to a height of three hundred feet and came
down safely. From that day to our Civil War, bal-
looning remained a spectacle of the circus and a sport
for the intrepid. But during the Civil War, balloons
were used for observation to a limited extent. Later
on, they were anchored by means of cables, for sight-
seeing purposes; and many is the person who, having
gone up a few hundred feet in a spherical balloon
swaying and tossing in the wind like a cork on rough
water, became seasick and weary as the result of a
rather harrowing experience. For observation pur-
poses, this tossing about of the spherical balloon made
its use uncertain; it was difficult to obtain exact data,
because the observer was frightfully seasick.

What substances to employ to retain hydrogen in a
balloon was ever a problem. Special varnishes made
of linseed oil were used in the old days of circus bal-
loons. The first "inflammable air" balloon made of

BALLOONS 3lSl

silk was launched on the European continent by the
Eoberta brothers and J. A. C. Charles in the year 1783.
G. J. Wright in 1803 suggested, however, strong cam-
bric muslin, rinsed in drying oil or varnished with a
solution of resin or gum lac with linseed oil. He found
that the compositions for varnishing balloons had been
variously modified, but, upon the whole, the most ap-
proved appeared to be the bird-lime of Faujas St.
Fond. However, he wrote: "As the elastic gum
known by the name of Indian rubber has been much ex-
tolled as a varnish, the following method of making
it, as practiced by Mr. Biancbard, may not prove un-
acceptable: Dissolve elastic gum in five times its
weight of rectified essential oil of turpentine, by keep-
ing them some days together. Then pour one ounce
of this solution in eight ounces of drying linseed oil
for a few minutes; strain the solution and use it
warm." He proposed that the parachute be con-
structed of varnished cambric muslin.

The first ones to deviate from the old spherical shape
to something of the kite idea were the Germans, who
made a balloon known as a Drachen, sixty-five feet long
and twenty-seven feet in diameter. This Drachen
had an open under-rudder which, filled with air, made
the balloon somewhat more steady than without it.
A series of tail cups, like little parachutes, served to
prevent the balloon from bobbing and swaying too
greatly. It was a long cylindrical object, with a series
of ropes from a band around its equator carried down
and concentrated at a ring. From this ring the cable
ran down to the ground. The Drachen was, however,
unstable in high winds. The likeness of the original

316 THE KEION OF KUBBEB

Drachen, with its various modificatioiis, to a German
sausage led to the adoption of the name "sausage" in
slang expression.

Captain Caqnot of the French army met the eitiia-
ti<m with a kite-balloon that had snch superior stability
in high winds, that it came rapidly into general nse in
the armies and navies of all the combatants. This new
balloon, which has been known as the Caqnot type of
kite-balloon, was ninety-three feet long and twenty-
eight feet in maximTim diameter; as osnally con-
stmeted, it had a capacity of 37,500 enbie feet of hy-
drogen.

The Caqnot balloon, in principle, consists of an elon-
gated, rubberized fabric envelope, larger at one end
than at the other. The mbberized fabric is a layer
of robber between two layers of thin, cotton cloth cap-
able of resisting the outflow of hydrt^en. At the lee
end, are stabilizers of much lighter mbberized fabric,
connected in snch a way that the wind blows into these
stabilizers, filling them out and causing the balloon
to soar np like a bite. Xear the top, two of them, some-
thing like big wings, have the appearance of elephant-
ears ; and one acts as a sort of a vertical tmder-nidder.
Even with these stabilizers the balloon would not he
steady enough in the wind, if it were not for a rub-
berized fabric diaphragm which lies inside on the bot-
tom of the balloon and is called a ballonet. The funo-
tioQ of this ballonet is to give a space of variable
volume, so that when the hydrogen in the balloon con-
tracts because of variation in temperatnre occasioned
by altitude the balloon may be kept taut. This taut-
Qess is accomplished by the inflow of air caught

BALLOONS

317

by a Bcoop on the under side of the envelope. The
air flows into this ballonet space, raises it, and main-
tains sufficient pressure in the envelope to preserve its
shape. Without the ballonet, the kite-balloon would
become a shapeless and unmanageable mass of flap-
ping fabric whenever the gas contracted. When the
heat of the sun expands the gas, the hydrogen presses
against the balloon, air passes out through the same
scoop, and the envelope is kept taut. But if there is
more expansion than the ballonet can accommodate,
another important device cornea into operation. This
is the automatic gas-valve located in the top, near the
front of the balloon, which operates at a determined
pressure to let out hydrogen and thus always to main-
tain the pressure in the balloon at a constant value.
By this combination of devices, there was made an
instrument of war observation, permanent and stable
in the wind. Its ability to ascend more than five thou-
sand feet gives to the observer a wide range of vision.
The basket cables are connected to the balloon by
rigging; in the basket, which is made of light but
strong wicker, are the observers with their instru-
ments.

When the United States went into the war, our army
and navy were virtually without observation balloons.
The only company in this country that had systematic-
ally studied ballooning was the Goodyear Tire & Rub-
ber Co. of Akron, Ohio. With remarkable foresight,
the officials of that institution had for a number of
years developed a balloon organization.

In the spring of 1910, with the aeroplane develop-
ment under way, P. W. Litchfield, vice-president of

THK KEIGN OF RUBBER

the Goodyear company, looked into the future and
saw great possibilities. He went to Europe in tite
summer of that year, made arrangements for a sup-
ply of the precise cotton fabric required, and in the
autumn began the experimental manufacture of free
balloons. The first airship attempt was the Akron,
which was made to fly across the Atlantic, but which
met with an untimely explosion in July, 1912.

The company continued to experiment with spherical
balloons and had a considerable number of trained
men engaged in their manufacture in 1917.

When the emergency came, all joined bands in whole-
hearted cooperation : the signal corps of the army, the
navy, the United States Rubber Co., the Firestone
Tire & Rubber Co., the Connecticut Aircraft Co., the
Knahenshue Manufacturing Co., the B. F. Goodrich
Co., and the Goodyear Tire and Rubber Company.

Balloon fabric as used in kite-halloons was of three
classes. The ballonet cloth weighed two ounces to
the square yard ; in it two plies were used with the
threads parallel, and a thin layer of rubber was prop-
erly vulcanized between them. So fine was this cloth
that there were 118 threads to the linear inch of warp
and filling. The main fabric of the balloon consisted
of two plies of fabric weighing two and one half ounces
to the square yard, one of them placed upon the other
on the bias, with three and one half ounces to the
square yard of rubber known as the sandwich layer
between them. This two-and-one-half -ounce cloth was
so fine that there were 128 threads to the linear inch
of width. After it was made up into fabric, a pull of
sixty pounds on a one-inch strip was required to break

BALLOONS 311

fit. It was a delicate, skilled, careful operation to
make balloon cloth ; only the finest of Sea Island cotton
or the Sakeilarides Egyptian cotton would answer.
There could be no imperfections, for each little knot
or each bit of dirt would mean a pinhole through which
the hydrogen would leak.

In the manufacture of rubberized balloon fabric,
the raw cloth is first placed over a glass table il-
luminated from below, where it is observed for im-
perfections. This cloth is then coated with a thin
layer of rubber cement. The rubber composition is
one chosen after many experiments; each manufac-
turer has probably a slightly different idea, but all
the compositions are subjected to sunlight tests and
other rapid determinations of length of life. Only the
purest, cleanest rubber of the highest grade is used,
and very little of any type of compounding ingredients
except those conducive to perfection, to resistance to
diffusion, and to resistance to the action of light and
heat. It requires as many as thirty-two thin layers of
cement to build upon the fabric the thickness of rub-
ber required.

After each layer of fabric has been spread and dried,
one of the layers is cut into pieces on the bias and
pressed upon the straight sheet with a thicker rub-
ber layer between. Great skill is necessary in order
so to lay on the rubber that the diffusion of hydrogen
through it is a minimum. This doubled, long roll is
■ithen wrapped upon a drum and vulcanized.
V The details of the manufacture of the envelope are
■those of a high degree of creative skill. Strips or
Bgores of fabric run longitudinally, each of these gores

THE EEIGN OP RUBBER

being made up of panels in which the warp threads
are perpendicular to the length of the gore. Seams
between the adjacent panels are made by overlapping
the fabric and carefully cementing the edges together.
Since dirt is so great an enemy of rubber, in punctur-
ing it, only skilled workmen, uBuaUy girls are per-
mitted to work in the balloon-room; and they wear
8oft-6oled slippers. Whenever balloons are handled on
the floor of the great assembly-rooms, they are never
dragged about on the cement 6oors, but are moved
about on vacuum cleaned carpets of heavy canvas.

After this long and careful process of manufacture,
our balloons during the war gradually were assembled.
Special riggers applied the rigging of rope. Certain
rubber compositions were used on the outside of the
envelope, designed after careful study to protect the
sandwich layer of rubber. The purpose of these com-
positions was to absorb the active or actinic rays of the
sun, and also to keep out oxygen from the air. We
generally adopted European standards of construc-
tion; but we developed our own rubber compounds,
times of cure, and methods of manufacture. American
fabric burned more slowly than European balloon fab-
ric, and thus when the balloon was struck by hostile
bullets it gave the men in the observation-baskets more
time to get away in parachutes.

Small Caquot-type kite-balloons were used by the
Navy Department for observation purposes on board
ships in the spotting of submarines. There were also
propaganda balloons. We find that up to the annis-
tice the rubber companies and others in the United
States produced 676 observation balloons for the

BALLOONS

army, of which 481 were shipped overseas, and that
they made 129 supply baUoons and 215 propaganda
balloons.

But these kites were not the only aircraft in which
rubber was used. For while fewer in number, diri-
gibles were better known to the public. These were
made for the Navy Department. The Bureau of Con-
struction and Repair had been studying dirigible con-
struction ; and in February, 1917, the Secretary of the
Navy was ordered to proceed with the construction of
sixteen such air-ships.

The B-type dirigibles were 160 feet long and of
85,000 cubic feet capacity. Equipped with one one-
hnndred-borse-power motor, they were capable of mak-
ing a speed of forty-five miles an hour, with an en-
durance of about sixteen hours. A larger ship known
as the C-type, was 192 feet long, with a gas capacity
of 190,000 cubic feet. This air-ship had a possible
speed of sixty miles an hour and an endurance of
forty-seven hours. It was one of this type that flew
in 1919 from Montauk to Newfoundland, with the ex-
pectation that it would take part in a transatlantic
flight. But unhappily, in a high wind it broke loose
from its mooring and was blown out to sea. This acci-
dent constitutes one of the many tragedies connected
with aircraft.

In making the rubberized fabric for the air-ship of
the non-rigid type, the same principles that have al-
ready been described in the discussion of kite-balloons
were used. The same care in the manufacture of this
cloth was maintained. The envelope was stronger be-
cause made of two plies of heavier cloth.

322 THE BEIGN OF EUBBEE

Because of the smallness of its size, its compara-
tively low cost, and the ease with which the envelope
can he erected or deflated for shipment, there are
great advantages in the non-rigid type of air-ship.
Its most serious disadvantage lies in its dependence
upon careful control of gas pressure within narrow
limits. If the pressure rises too high, the envelope
may burst, although ampie valves of a proper design
limit this risk. It is, however, equally fatal for a loss
of pressure to permit the envelope to lose its shape,
because nothing is quite so dangerous as a sagging
envelope.

AU the steering-equipment, rudders, fins, and the
car are slung upon the outside of this envelope by
wire or manila rope through cemented-on patches.
During a wind the stresses in a sagging envelope may
therefore be enough to tear this light thin cloth ; with
tearing of the cloth, comes destruction of the balloon.

Consequently the problems in dirigible construction,
and we may say in all types of balloon construction,
lie largely in having the strongest and lightest fabric;
one of sufficient strength so that when reasonably well
designed the application of sudden and irregular loads
upon any of the attachments cannot tear the cloth.
The fabric must be permanent in the sunlight. Resist-
ance to the diffusion of hydrogen is an important
problem in practical operation. While it is always
required that this be kept at a minimum, when one
considers the losses of hydrogen from the operation of
valves in the expansion of the gas on ascending into
the sun, it is safe to say that losses by diffusion are
minor factors.

BALLOONS 323

Tile so-called semi-rigid air-ship also has an enve-
lope of rubberized fabric. A ^rder keel gives it stiff-
ness and renders it less dependent on gas pressure
for the maintenance of shape. Here a lower gas pres-
sure and hence a lighter weight of fabric is permis-
sible than in the non-rigid air-ship. The bending
forces are so distributed that the keel takes compres-
sion while the fabric receives a moderate tension.
Therefore, it is possible to give the serai-rigid ship
an exceptionally light construction, and so to permit a
relatively greater useful load to be carried to a higher
altitude than with other types of equal size. With
the exception of the keel in the envelope, small, semi-
rigid air-ships resemble non-rigids in their general
features. They are more costly and less easy to erect.

The most spectacular type used during the war was
the rigid air-ship of the Zeppelin type, which employed
very little rubber in its construction. Probably it is
the largest and most complex of all known types of
aircraft — largest in carrying capacity, highest in
speed, most intricate in the structure of its dura-
luminum girders and wire. Triangular-shaped gir-
ders make up its backbone. On the outside a ply of
cloth is tightly drawn around the girders and coated
with aluminum, water-tight "dope." Inside the gir-
ders, within the hull structure, are arranged sepa-
rate gas-bags, usually made of a single ply of light
cotton cloth lined with a thin layer of so-called "gold-
beater's skin," to give gas tightness. Goldbeater's
skin is made from the entrails of cattle; it is a thin
membrane almost perfectly gas-tight and very light.
^L Since air-ships have a promising future, there

324

THE REIGN OF RUBBER

ia a large opportunity for development work in'
the Bcientific construction of fabrics to permit very
piuch greater resistance to tearing, with no increase
in weight. The rate of deterioration of rubber in the
sunlight through oxidation is one of the important
problems, but one which, I believe, has been largely
solved. Rubber fabric, though, should be applied in
greater degree to these aircraft. When the problems
of construction, explosion, permanence, and strength
of fabric are more nearly solved, the great future of
the air-ship will be more completely realized.

The time will surely come when air-ships of enorm-
ous size, capable of remaining in the air even if an en-
gine stops, vrill run between London and New York or
across the continent. Then the business man will be
able to go from New York to London in forty-eight
hours. Since speed in business has come to be so
necessary, it seems not unlikely that the demand of
the future will require a minimum of time in long-
distance transportation; probably this high speed moat
certainly and safely can be attained through lighter-
than-air craft.

CHAPTER XXI

THE FUTURE OF RUBBEE

A laudable future for any industry, man, article, or
substance can be aebieved only because of service
rendered to mankind. "For whosoever bath, to him
shall be given, and he shall have abundance ; but who-
soever hath not, from him shall be taken away even
that which he hath." This fundamental truth forma
a basis for prediction. It is idle for one to dream
when dreams but express wishes. It is useless to pre-
dict, when predictions formulate only hopes. One
can, however, forecast possibilities of growth based
upon natural properties of usefulness. "Whosoever
hath" means characteristics, physical in the case of
rubber, mental and moral iu the case of an individual
man, a company, a corporation, or an industry. Rub-
ber and rubber companies, we believe, can become
greater in a commercial sense only if the qualities of
rubber are superior and if they render valuable service
to those who would use their products.

Does rubber have properties natural to it which,
when expressed in the form of articles made and used,
will probably increase the extent of its service T
The question is its own answer. There is no sub-
stance, and essentially every one known has been tried,
to take the place of rubber. Rubber seiTes, and serves
remarkably. If the pages which I have thus far

326

THE BEIQN OF EUBBBB

written have accomplished their purpose, they indicate
certain fundamental characteristics by which rubber
is distinct from any other known material; and they
show that rubber has worked itself into life economy
by virtue of the fact that it performs definite, valuable
functions, not artificially stimulated but natural!/
possessed and given. Some phases of these character-
istics may be reviewed from a different point of view.

Although food, shelter, and clothing are the three
necessities for our physical welfare, the relations with
our fellow-men give us happiness, and these relations
are modified greatly by means of conamunication ai^fi
transportation. We have already spoken of the tele-
phone and the telegraph, with their rubber parts, by
which wire communication is maintained.

The good fellowship among men is in no small way
engendered by freedom of intercourse over wires.
There are millions of intelligent human beings on ou"
earth to whom the telephone has not come — a va^
field for expansion with boundless possibilities for
service. The telephone will span the sea. Distant
people will talk to each other. When persons all over
the world can understand each other and can freely
and rapidly communicate, then, and not till then, will
wars cease and peace on earth be a reality.

Communication without wires is a new development
which has come along so rapidly in the last few years
that it bids fair to extend to almost unlimited possibil-
ities. Since the uses to which radio can be put are
diversified, it is certain to bring about changes in
life's every-day affairs. It will, through finely devel-
oped broadcasting stations, serve to bring in to homes,

THE FUTUEE OF RUBBER

327

news, communications, entertainments, and education
of wonderful value. For communication from ship
to ship or from shore to shore and between aiiroplancs
in the air, for making ships safe on ocean and lake
when in heavy fogs, for out-of-the-way places where
\ ire installation would be expensive and impracticable,
wireless constitutes, in addition to the conveying of
regular commercial messages, a development of vast
iiiiportance.

What part will rubber play in wireless communica-
tion of the future! It plays a part to-day; for, of all
t'le substances thus far known, rubber is the one which
for wires possesses the greatest flexibility and insulat-
ing properties, and which in the form of hard rubber
has greater dielectric capacity than any other sub-
fltance, with less dielectric loss. The use of hard rub-
ber and other rubber products in connection with radio
^^is every possibility of increased use.
^^Eegardless, however, of both wire and wireless com-
ffiunications, we still do and doubtless always shall
reduce our ideas to writing. The permanent record of
business intercourse, the printing of books and news-
papers, lie in the field of communication which has been
developed to a great degree already, but which has pos-
sibilities for further growth. We have spoken already
of the typewriter. I wonder whether more parts of it
will not ultimately be made of rubber, — a construction
reducing the noise to a degree approaching silence?
Perhaps some enterprising inventor will study the
voice-waves, ao that a telephone typewriter will be
worked out, permitting the direct transfer of the voice
to letters on paper. To wonder whether rubber will

THE REIGN OF RUBBEB

play a part in aach an enterprise, is, I snppose, to
dream.

In the printing of books and newspapers, the last
few years have witnessed changes produced by the use
of the rubber ink-spreading rolls, which have given
marked eEBciency and improvement. Despite the fact
that oils are used for inking purposes, rubber
has been found to resist them relatively well, to with-
stand in these rolls the change of climate, and to give
a marked superiority to the permanence of operation
of printing-presses. When, however, in connection
with rubber ink-spreading rolls, the water-ink, which
is a development of recent growth, comes to be gen-
erally used, all phases of the printing industry will
economize time and money and gain higher speed.
This development of considerable value will have been
made possible by rubber and rubber rolls.

Because supplies of wood for wood pulp are rapidly
decreasing, materials must be found to serve in the
manufacture of paper. We shall be able to grow, with-
out doubt, a sufficient quantity of cellulose ; if, though,
it fails to have the properties which wood pulp pos-
sesses to-day, it may be necessary to follow out the
suggestions recently made of using rubber in connec-
tion with it. By virtue of its adhesiveness, rubber
may give us book and news-print paper of greater value
than we now have. Something is certain to be done,
for the need is here and will become more and more
marked with time.

But it is in the field of transportation that rubber
will continue to extend its usefulness. Whatever may
be your definition of the word "civilization", one

THE FUTUBE OF EUBBEE

thing ia tme : the difference between human life as we
live it and the lives lived by our forefathers back over
the centuries lies in the means that have been used to
overcome elemental conditions. Civilization, be it
moral or physical, is marked by a development of hu-
man facilities. To use and enjoy them, men and goods
must be moved from place to place. Thus transporta-
tion holds the key to the world's progress; and "the
history of the highway by land and sea is the history
of civilization and the mark of the progress of man."
"We have but to compare travel upon the continent
in the days of the old French diligence to realize how
completely our lives have altered in a short span of
years because of improved transportation facilities.
In an interesting volume on "Travel in the Last Two
Centuries of Three Generations" by S. R. Roget, he
describes a trip taken in 1818 in the United States.
He says that Dr. P. M. Boget on May 18 of that year
left Philadelphia and arrived the same night at Eliza-
bethtown, eighteen miles west of Lancaster, and again
on May 29 he passed through Harrisbnrg to Chambers-
burg. He remarks that from Harrisburg the roads
were very bad. The bridges were constructed of wood,
except the piers, which were of atone, and were cov-
ered by wooden roofs. "The roads, instead of wind-
ing round the mountains, are carried almost straight
across them, and appear to have had very little more
labor bestowed upon them at any time than that of
clearing away the timber which grew upon them."
The difficulties of transportation described in the an-
ecdotes of this interesting volume leave no doubt in
our minds that our modem life could not be lived with-

THE REIGN OF RUBBER

out the railroads or without improved highways.
Thus, our human progress has been built upon the free
movement of goods and of men. Just as England has
been made great by the use of the ocean as a highway,
so the United States has in the short space of a hun-
dred years been made great by her rail transporta-
tion, the most advanced and complete the world has
ever seen.

Rubber, just as certainly as steel, has aided the de-
velopment of the railroads, the signaling system, the
ocean ships, and many other fundamental things that
have made transportation changes possible. In va-
rious ways unsung it plays a great and vital part.

During recent years, however, we have watched the
growth of a new form of transportation— that of the
trackless car, the motor-car, the truck. Here, in a
most spectacular way, the rubber tire and various
other rubber parts have come to be vital. In the fu-
ture, the development of the improved highway, be it
the macadamized road or the cement or brick pave-
ment, will surely play an increasingly important part
in transportation. The railroads ever wiU be the main
arteries upon which tonnage and speed can be main-
tained, but the highway more and more will become the
feeder. In our cities the trolley-car conveys ns from
place to place. The motor-bus is the trackless street-
car of the future. It is economical, convenient, quiet,
and subject to a degree of flexibility not possessed by
the electric tram. No dream is necessary to look for-
ward to cities in which motor-buses will be the pre-
dominant means of human conveyance. So far aa
goods are concerned, with the railroad it is necessary

THE FUTURE OF EUBBER

to load them at a factory, haul them to a station, un-
load them in a car, unload them again at a distant ter-
minus, load them into a van, haul them to the consumer,
and unload them again. The motor-truck, contrari-
wise, permits one loading and one unloading, a saving
in energy and time.

A vast extension in the use of the motor-car is a log-
ical forecast, and with it an expansion of the rubber
industry. In 1896 there were but four gasolene auto-
mobiles in the United States ; in 1916 there were 3,500,-
000; and at the beginning of 1922 there were nearly
10,500,000 — one car for every ten people. There are
about 3,000,000 motor-cars on the farms, that is to say,
the farmers own about one third of the motor-cars ;
while in the cities of 500,000 or over there are only 9
per cent, of this total registration. There are in
America 24,351,676 homes. It is hardly possible that
in the future there will be one car for every home, but
there are more than 6,750,000 farm homes from which
motor-ears might serve well to carry food to city cen-
ters. Eventually farmers will insist upon further im-
proved highways, and demand the same facilities for
communication with their fellows that are afforded to
others. So far as the ability of the people of this
country to purchase motor-cars is concerned, it is quite
probable that a registration of 15,000,000 passenger
and commercial cars within the next five or six years
will be realized.

These figures refer only to the United States, which
has 6 per cent, of the population of the world, 7 per
cent, of the land, and 83 per cent, of the motor vehicles.
In the great continents of Asia, Africa, and South

333

THE EEION OF EUBBEE

ion of motor- I
!rica. Great I

America, as well as Europe, the registration c
cars has not approximated that in America.
Britain and Ireland, for instance, afford only an aver-
age of one car for every 95 people ; while China, on the
other hand, has one for every 54,708 persona. The
wealth of many countries is sufficient to afford motor-
cars to carry food products from farm to consumer.
It seems reasonable to suppose that the countries where
highway development has proceeded most rapidly will
be first to demand and obtain sufficient motor-cars.
Thus, the countries of Europe will, in all probability,
rapidly acquire them. In the other countries, how-
ever, the spread of the motor-car will depend upon
highway development. With this development will
come exchange of commodities and personal relations
that will lead to increase in the national wealth and
abihty to purchase motor-cars. As a consequence, the
need for rubber goods of all descriptions will grow
manifold.

Let us see what these possibilities mean to the fu-
ture production of tires in the United States. The
world registration of cars at the beginning of 1922 was
12,528,000, an increase of 1,606,000 over that of the pre-
vious year. In the United States the increase will
probably not continue at that rate; but, on the other
hand, elsewhere a higher rate will no doubt
be attained. Assuming the world to add 1,606,000 au-
tomobiles and trucks each year for six years, there
would be at the beginning of 1928, 22,164,000 cars, a
total increase of 75 per cent., a change not only possible
but highly probable. At the rate of three tires per car
per year, the rubber industry of the world would sup-

THE FUTURE OF RUBBEE

ply more than 66,000,000 tires to the consumers in that
year. They will be cord tires for passenger-cars, with
a marked increase in the use of the solid tire on the
bus and the truck. Including inner tubes, we assume
a weight of fifteen pounds of crude rubber to the tire.
For transportation purposes, therefore, we are justi-
fied in a prediction of a use for tires alone of f
000,000 pounds or 440,000 long tons of raw rubber in
1928. The productive capacity for tires in America
to-day is probably not far from 44,500,000 yearly, and
that of all other countries, 10,500,000, or a total of
55,000,000, The world will need to increase its capac-
ity before 1928 by 11,000,000 tires a year to care for
the demand.

In transportation in the sky rubber has played and
will continue to play a most vital part. The dirigible
has come to stay; the fatal accidents that have startled
us during the last few years serve but to indicate how
we have attempted to run ahead of demonstrated
experience. Rubber in the making of balloons to hold
hydrogen or helium has proved itself valuable and will
prove itself more so. The business man, with his con-
tract to be signed, will fly from his office to the trans-
atlantic dirigible field, where the great three or
four-million-cubic-foot aircraft will be moored. He
will ascend in the elevator inside a mooring mast and
walk into his cabin as readily as he now does into the
state-room of the ocean liner. When all is ready the
dirigible will move rapidly and safely, avoiding the
storms and the high winds by her ability to rise above
them or fly below them. Within the space of a day
the business man will find himself landed upon the

THE FUTURE OP BUBBER

the cooperation of chemists in finding poisons which,
when applied to the ground or other places during his
hibernation periods, will kill him. If the boll-weevil is
not definitely restricted, then the predictions of the
Department of Agriculture may unfortunately be
realized, for one of the investigators says: "To-day
I predict that unless something be done that will defi-
nitely and speedily stop the crime of early planting,
the entire cotton growing industry In the United States
south of the thirty-second degree of latitude will
within the next ten or fifteen years be completely wiped
out of existence. And that within the next thirty
years the great cotton industry of the United States,
formerly considered almost like a monopoly which,
from a world production standpoint, has already been
reduced by early planting from 67.9 per cent, in 1905
to 56.7 per cent, in 1915, will have to take a back seat
to that of British India." Cotton, therefore, is men-
aced, but can be saved. Perhaps rubber milk sprayed
upon the hibernation homes of the weevU might en-
tangle him and hinder his growth.

The research laboratories in the great factories em-
ploy chemists, physicists, and engineers whose business
it is to create processes and products. New uses
for rubber are constantly finding their way into
the markets. The dreams of to-day become the real-
ities of to-morrow; possibly, often not in the same
form in which they were originally dreamed, but
nevertheless the dream made the suggestion. This
intense activity will result in articles of increased value
and service to the consumer. Rubber is a substance.

THE REIGN OF BUBBEE

which, in its ramifications extended by the forces of
investigation, wUl certainly serve humanity in many
more forms than it does to-day.

AbrsBion, resistance to, 65

Acetone eitract, 104

Aceelerators, inorganic, 50 ; or-
ganic, 53, 115; theory of, 52,
115

Acit&ge, plantation, SO, 33S

African rubber, 84

Aging, 111, lis

Air-brake, 276

Akron, 14

Aniline, 53

Antimony suTpbide, 62

Automobile, future of, 331 ; hii-
tory of, 128; BtatiflticB, 331

Balata, 87

Balloona, 312; ballonct, 316;
Caquot, 316 ; dirigible, 321 ;
Drachen, 316; fabric, 314, 318;
future, 323, 333; goldbeaters
Bkin, 323; history, 313; kite,
313; observation, 320; Zeppelin,
323

Bands, 233

Barytes, 46

Baeeballg, 187; protectors, 188

, tire

130

Bell, Alexander G., 218

Belting, axle lighting, 269; con-
Teyor, 260 ; elevator, 278 ;
Ucings, 268 ; power trang-
misBion, 264

Bicyclee, history, 120; Btatistica,
126

Billiard cushions, 204

Bloom, 109

Boots and eboea, claasifl cation,
170; color, 178; designing, 172;
history, 10, 11, 168; manu-
facture, 173; production, 171;

rubbers, 1T2; styles, 171; var-
nish, 177
Brazilian rubber industry, 66
Brochedon, 25
Cables, 20B; gulta percha, 222,

history, 224; rubber, 223
Calender, 41; friction, 42, 266
Cam eta, 70
Canning, history, 200; statistics,

291
Caoutchouc, derivation, 6
Carbon black, 46, 50, 60, 61;

particle size, 117
Castilloa, 72

Catalysts, see Accelerators
Ceara, 84

Chaffee, Edward M., 8, 35, 36, 41
Chemistry, 99
Chewing gum, 87
Chicle, 87
Chrome green, 62
Cboate, Eufus, 26
Clay, 40

Clothing manufacture, 1B2
Coagulation, chemistry of, 101 ;

plantation rubber, 77; wild

rubber, 68
Columbus, Christopher, 5, 63
Compounding, 33, 44, 62
Consumption, crude rubber, 82;

future, 335
Cotton, problem, 337. See Fabric
Dipped goods, 255
Divers suits, 281
Drying rubber, 32
Dunlop, John B., 121
Dynamo, 206
Elastic limit, 57

342 I

Electricity. 205

Energy, rubber, 56, 68, 60

Erasers, 232

Pahrip, bicycle tire, 126; cord
thread, 132; in reclaim. S
pneumatic automobile, 13
procesHing for tires, 13
iquare woven, 132

FareJay, 18. 208

Fire engines, 235; ateam, 23T, 239

Flap. tire. 135

Football bladder, 204; guard, 204

l>'rictioning, 42; belt, 266

Friction, belt, 266; tire, 131

GasJietH, 276

Gas masks, 298; Akron Tissot,
308; description, 302; flutter
valve, 303; hose, 303; P. H.,
302; H-2, 302; respiratorg, 302,
304; Tissot, 304

Gas warfare, hiatory, 300; as
weapon, 310

Gtovea, lineman's, 215; eurgeon'

'; Mw, I

; green H, hoae

235

Golf, history of,
for, 285

Golf balls, bursting force, 20O;
characteristics, 197; descrip-
tion, 193; ducking, 192; energy
imparted to, 190; flight, 197;
gutta percha, 189 ; Haskell,
191; hiafory, 189; manufacture,
105 ; tension, 195 ; statiatics,
168

Goodyear, Charles, 0, 21, 41, 50,
215, 280

Goodyear, Nelson, 217

Grading plantation rubber, 78

Grain in rubber, 106

Guayule, 84

Gutta percha, 87; cables, 222

Hancock, Thomas, 7, 12, 18, 20,
25, 30, 71, 129, 153, 182, 237

Hard rubber, original, 217; chem-

ical composition, 112, 217
218, 230
Haskell. Coburn, 191
Hay ward, Nathaniel, 22
Heels. 180
Heriasant, 85

HeJTera-Tordeaillas. Antonio, 63
Hevfa- bra sinensis. 86, 71
Hooker, Sir Joseph, 72
Hose, airbrake, 276; air-drill,
275; air-signal, 277; coupling,
238; fire-history, 236; manu-
facture, 242; storage, 247; test-
ing, 244; garden, 285; gasolene,
280; oil, 278; radiator, 275;
railway requirements, 277 ;
sand-blast, 275; spray, 289;
steam-beating, 277; suction,
275; BtatisticB, 277
Hospital, rubber for, 349
Howison, James, 71
*-4nsu]ated wire, aging, 213; manu-
facture, 207; railway signaling,
210; telephone, 221; war-time
uses, 221; for homes, 212
Jar-rings, 202; testing, 203
Jeffery, Thomas B., 123
La Condamine, 64, 08
Latex, 66-; RDalysis, 100; chemis-
try, 100; colloiaal state of, 09;
weight per gallon, 101
Leather, artiflcial rubber from, 20
Life-preservers, 21, 280
Lime, 52

Lineman's blanket, 214
Liners, 42, 140
Litharge, 46, 62
Lithopone, 62
Machinery, 30

Mackintosh, 7, 19, 182, 237"
Macquer. 65
Magnesium oxide, 62
Markham, Clements, 72
Marks, Arthur H., 63, 94
Masticator, 19, 30, 35, 40

Matting, 250

Milking machinea, 295; rubber

parts for, 29o[ care of rubber

for, 296
Mineral rubber, 61
Mitchell, N. Chapoiao, SI
Mixer, 30, U
Mixing, aa
Motor-bus, 151, 154
Motor-truck, 160; electric, 152;

history of, 152; service of, 166
Oenslager, George, 53
Oil-fields, rubber in, 278
Ostrotnislensky, 114
Packing, 273; superheat, 274
Palmer, John F., 124, 138
Paper, rubber for, 328; industry,

278
Par& rubber, 68
Parkee, Alexander, 113
Peachey, S. J,, 114
Peal, Samuel, 7, 83
Permanent set, 68
Photomicrographe, 116
'Tickle," 29
Pigments, 46, 116; claiiification,

117; particle size, 117
Plantation industry, 71; acreage,

80; growth, 80; location, 80;

origii\, 71
Polymerization, 104
Polysulphide, 116 »

Pope, Alfred A., 127
Foppenhusen, Conrad, 218
Priestley, Joseph, 6, 66
Printers' rolls, 328
Production, crude rubber, 80 ;

future, 336
Proteins. 100, 103, 105, 106
Badio, rubber for, 226; future of,

327
Railway signaling, 210
Baincoats, 182
Beclaimed rubber consumption, 97

lEX 343

Reclaiming, 88; acid process, 92;

alkali process, 94
Resins, 103, 104
Robins, Thomas, 26B, 272
Roxbury India Rubber Co., 8, 20,

Rubber boom, 81

Rubber, chemistry, B9; colloidal
state of, 105; definition of, 16;
history, 5, 63; hydrocarbon,
103; structure of, 103; solu-
tions, 7, 10, 05, 107; plasticity,
29

Rubber industry, definition of, 15,
29, 42; future of, 325; growth
of, 7; history of, 7

Sernamby, 70

Shrinkage, 70

Shrub rubber, 85

Bloper, Thomas, 138

Smoked sheet, 78

Smoking wild rubber, 68, 78

Soles, 181

Solvents, effect on rubber, 107,
116; petroleum as, 66; turpen-
tine as, 65

Sponges, 283 I

Sport, rubber in, 187 |

Spreading, 40, 183

Stamps, 233

Steam, use of in vulcanization, 23

Storage batteries, 228

Storage, crude rubber, 79; rubber
goods, 118

StresB-etraiu curve, 60; effect of
accelerators on, 64

Sulphur, 9, 22, 20, 28, 51, 110;
combination with rubber, 108

Sulphur chloride, 113

Synthetic rubber, 86, 103

Tapping, plantation methods, 76;
wild rubber, 67

Telephone, 218

Tennis, history, 202

Tennis balls, 202^

344

Tennis ahoes, 179

Terpeoee, 103

Testing rubber. 49

Thomaon, Robert W., 121

Tiling, 250

Tillingbaet, P. W., 122

Tires, bicycles, 120; biatoiy, 120^
manufafturei 125; cord,
pneumatic automobile,
pneumatic truck, 162; solid,
152; future demand for, 332

Torquemada, 04

Transportation, 149 ; futiire ol.

Tread, tire, 60, 134

Tube, inner, 134, 144; formnla, 47

Tubing, drainage, 200; Carrel-

Dakin, 201
Typewriter, 230; platens, 231
Ultramarine blue, 62
Van der Heide, John, 230

, coefficient of, ill;
discovery of, 9, 22;
m pounds for, 114;

Vermilion, 62

Viacosity, 107

Vulcanization, coefficient of, lH
cold, 113; discovery of, 9,
organ iu compounds for,
Feacbey proceM, 114; time and
temperature, 28, 110; theory of,
lOe, 112; without sulphur, 114

Washing rubber, 31; loss on, 70

Water bottles. 296

Water-ptoofing, 7, 182; See
Spreading

Weher, Carl O., 112

Webster, Daniel, 26

Westinghouae, George, 276

Wliite lead, 9, 50

Whiting, 46

Wickham. Sir Henry A., 71

Zinc oxide. 46, 60; particle site.
117; for resistance to abrasion,
S5

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Full text of "The reign of rubber"

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